McPhilly is conducting a study on the amount of money a customer spends on each visit to the restaurant. The company uses the receipts from 1 McPhilly to conduct the study. The company found that the mean amount spent is $11 with a $3 standard deviation. A.


a. What type of sampling method was used?


b. What is the probability that a customer spend less than $14 each visit?


c. What is the probability that a customer spends more than $7 each visit?


d. The customers were asked to respond to the following survey question, determine if the question is biased. Explain why or why not?


How does our food compare to PhillyBurger?

In summary, if the input graph G(V, E) has a negative weight cycle, there are no solutions to the single-source shortest path problem.

In the single-source shortest path problem, the goal is to find the shortest path from a given source vertex to all other vertices in a graph G(V, E), where V is the set of vertices and E is the set of edges.
If the input graph G(V, E) has a negative weight cycle, then there are no correct solutions to the single-source shortest path problem. This is because the presence of a negative weight cycle allows for a path with decreasing total weight, as you can continually traverse the cycle to reduce the path's weight. As a result, the shortest path is undefined in this case.

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The remaining money to buy supplies for next year's school play is $575.

Number of adults = 80

Number of children = 20

Cost of adult ticket = $8

Cost of children ticket = $3

Total cost donated by the school = $125

Total money collected by selling ticket= 80×8 + 20×3

Total money collected by selling tickets = 700

Remaining money to buy supplies for next year's school play = total money collected - total donated money

Remaining money tot buy supplies for next year's school play = 700 - 125

Remaining money tot buy supplies for next year's school play = 575

Remaining money tot buy supplies for next year's school play is $575

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The question is incomplete complete question is :

What's the answer to this question: There were 80 adults and 20 children at a school play. The school collected $8 for each adult's ticket and $20 for each child's ticket. The school donated $125 of the money from tickets to a local theater program and used the leftover money to buy supplies for the next play. How much money does the school have to buy supplies for the next play?

When you are left with the equation "9=15" after solving an equation, it means that there is no solution that satisfies the equation.

Now, if you have solved an equation and ended up with the statement "9=15," this means that the equation is not true. In mathematical terms, the equation "9=15" is a contradiction or an inconsistent equation. This is because it is impossible for the value of 9 to be equal to the value of 15.

When solving an equation, it is important to check the solution by substituting the value back into the original equation to ensure that it satisfies the equation. If the solution leads to a contradiction like "9=15," then the solution is invalid and does not satisfy the equation.

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The results show a different pattern than for the contiguous states

a. To create a new Season variable with values "Winter," "Spring," "Summer," and "Fall," we need to use the MONTH function in Excel to extract the month from the date, and then use a series of IF statements to assign each month to its corresponding season. Here are the formulas to use:

For the Heating Degree Days sheet:

=IF(OR(MONTH(A2)=12,MONTH(A2)=1,MONTH(A2)=2),"Winter",IF(OR(MONTH(A2)=3,MONTH(A2)=4,MONTH(A2)=5),"Spring",IF(OR(MONTH(A2)=6,MONTH(A2)=7,MONTH(A2)=8),"Summer",IF(OR(MONTH(A2)=9,MONTH(A2)=10,MONTH(A2)=11),"Fall",""))))

For the Cooling Degree Days sheet:

=IF(OR(MONTH(A2)=12,MONTH(A2)=1,MONTH(A2)=2),"Winter",IF(OR(MONTH(A2)=3,MONTH(A2)=4,MONTH(A2)=5),"Spring",IF(OR(MONTH(A2)=6,MONTH(A2)=7,MONTH(A2)=8),"Summer",IF(OR(MONTH(A2)=9,MONTH(A2)=10,MONTH(A2)=11),"Fall",""))))

b. To find the mean, median, and standard deviation of Heating Degree Days (HDD), broken down by season, for the 48 contiguous states location (code 5999), we need to use StatTools. Here are the steps:

Open the StatTools Descriptive Statistics dialog box by clicking on the Descriptive Statistics button on the StatTools toolbar.

In the Input Range field, select the range of HDD values for location 5999 (excluding the first and last rows that contain missing values).

In the Group By field, select the Season variable we created in part a.

Check the Mean, Median, and Standard Deviation checkboxes under Statistics.

Click OK to generate the results.

To create side-by-side box plots of HDD, broken down by season, we can use the Box Plot dialog box in StatTools:

Click on the Box Plot button on the StatTools toolbar to open the Box Plot dialog box.

In the Input Range field, select the range of HDD values for location 5999 (excluding the first and last rows that contain missing values).

In the Group By field, select the Season variable we created in part a.

Check the Side-by-Side box to create a side-by-side box plot.

Click OK to generate the plot.

Comment on the results:

The mean and median HDD values are highest in Winter and lowest in Summer, which is what we would expect. The standard deviation is also highest in Winter, indicating greater variability in heating needs during that season. The box plots confirm these findings, with Winter showing the greatest spread of values and a higher median than the other seasons. Summer has the narrowest spread of values and the lowest median.

c. To repeat part b for California (code 0499), we simply need to change the location code in the formulas and dialog boxes:

In the formulas for the Season variable, replace "A2" with the appropriate cell reference for the date column in the California sheet.

In the StatTools dialogs, select the range of HDD values and the Season variable for location 0499 instead of 5999.

The results show a different pattern than for the contiguous states. HDD values in California are highest in Winter and Spring, and lowest in Fall and Summer. This is likely due to the mild climate in California

The mean (average) of a data set is found by adding all numbers in the data set and then dividing by the number of values in the set. The median is the middle value when a data set is ordered from least to greatest.

There are several kinds of mean in mathematics, especially in statistics. Each mean serves to summarize a given group of data, often to better understand the overall value of a given data set. Pythagorean means consist of arithmetic mean, geometric mean, and harmonic mean.

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Answer:

Step-by-step explanation:

Area = W x L

Area = 42

all give 42 as a result

The calcuulated cost of 16 pencils and 10 notebooks is $5.84

From the question, we have the following parameters that can be used in our computation:

As a system of equations, we have

7x + 8y = 4.15

5x + 3y = 1.77

Where

x = pencils

y = notebooks

When solved graphically, we have

x = 0.09 and y = 0.44

This means that

x = pencils = 0.09

y = notebooks = 0.44

So, we have

16 pencils and 10 notebooks = 16 * 0.09 + 10 * 0.44

Evaluate

16 pencils and 10 notebooks = 5.84

Hence, the cost of 16 pencils and 10 notebooks is $5.84

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The hypothesis test is right-tailed and direction is specified, and the given population parameter is greater than the specified value (more than $500). So, the correct answer from given options is B).

The hypothesis test is right-tailed because a direction is specified. The null hypothesis assumes that the average tax refund is equal to or less than $500, while the alternative hypothesis assumes that the average tax refund is greater than $500.

Therefore, the test is designed to detect if the population parameter is greater than the specified value, making it a right-tailed test. So, the correct option is B).

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For the relations on the set of all functions from Z to Z, the relations out of these are equivalence relations are (a), (c). The relation (b) lack of transitive, (d) and (e) does not hold any property.

A reflexive, symmetric and transitive relation on a set is called an equivalence relation. Now, we have to check all relations on the set of all functions from Z to Z.

a) Set is defined as {(f, g) | f (1) = g(1)}, we check all three properties hold or not,

So, it is equivalence relation.

b) Set is [tex]{(f, g) |f (0) = g(0) or f(1) = g(1)}[/tex]

So, it not equivalence relation.

c) Set is defined [tex]{(f, g) | f (x) − g(x) = 1 for all x ∈ Z}[/tex].

It is not equivalence relation, because not reflexive and not symmetric.

d) Set is defined as [tex]{(f, g) | for some C ∈ Z, for all x ∈ Z, f (x) − g(x) = C}[/tex].

It is an equivalence relation.

e) Set is [tex](f, g) | f (0) = g(1) and f (1) = g(0)[/tex].

It is not equivalence relation because no one properties are hold here.

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The test statistic for this test is -0.213.

To test the hypothesis that two populations have the same mean, we can use a two-sample t-test. The test statistic for this test is calculated by taking the difference between the sample means and dividing it by the standard error of the difference.

In this case, the sample averages are 6 and 7, and the standard deviations for the two samples are 16 and 15, respectively. Both samples have 32 observations.

To calculate the test statistic, we first need to calculate the standard error of the difference. This is given by:

SE = sqrt[(s1^2/n1) + (s2^2/n2)]

where s1 and s2 are the standard deviations for the two samples, and n1 and n2 are the sample sizes. Plugging in the values we have, we get:

SE = sqrt[(16^2/32) + (15^2/32)]
  = 4.698

Next, we calculate the t-statistic:

t = (x1 - x2) / SE

where x1 and x2 are the sample means. Plugging in the values we have, we get:

t = (6 - 7) / 4.698
 = -0.213

The test statistic for this test is -0.213.

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To determine the number of ways you can achieve a 5-card hand without repeats from a deck of 52 cards, we can use the formula for combinations:

C(52, 5) = 52! / (5! * (52-5)!) = 2,598,960

This means that there are 2,598,960 ways to draw a 5-card hand without repeats from a standard deck of 52 cards.

In order to find the number of ways you can achieve a specific 5-card hand from a standard deck of 52 cards, you'll need to use combinations in discrete math. Combinations are used to calculate the number of ways to choose a certain number of items from a larger set, without considering the order of the items.

In this case, you want to choose 5 cards from a deck of 52 cards. Using the combination formula, you can determine the number of ways to do this:

C(n, k) = n! / (k!(n-k)!)

Where n is the total number of items (52 cards), k is the number of items you want to choose (5 cards), and ! represents the factorial function (e.g., 5! = 5 x 4 x 3 x 2 x 1).

Using the formula for your situation:

C(52, 5) = 52! / (5!(52-5)!)
C(52, 5) = 52! / (5!47!)

Calculating the factorials and dividing, you get:

C(52, 5) = 2,598,960

So, there are 2,598,960 ways to draw a 5-card hand from a standard deck of 52 cards without repeats.

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To investigate whether there is convincing evidence, at a 5 percent level of significance, that a longer hand length is associated with a decrease in the time to complete the 100-meter freestyle, the researcher should use a linear regression t-test.

1. The researcher collects data on hand length and 100-meter freestyle completion time for twenty randomly selected swimmers.
2. Calculate the correlation coefficient (r) to measure the strength and direction of the relationship between hand length and freestyle completion time.
3. Perform a linear regression analysis to obtain the slope (b) and the y-intercept (a) of the best-fit line.
4. Conduct a linear regression t-test to determine if the slope (b) is significantly different from zero at a 5 percent level of significance.
5. If the t-test results in a p-value less than 0.05 (5 percent level of significance), there is convincing evidence that a longer hand length is associated with a decrease in the time to complete the 100-meter freestyle.

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The Delphi method is not a quantitative forecasting method.

What is statistics?

Statistics is the branch of mathematics that deals with the collection, analysis, interpretation, presentation, and organization of data. It involves the use of mathematical methods to gather, summarize, and interpret data, which can be used to make decisions or draw conclusions about a population based on a sample of that population.

The Delphi method is a qualitative forecasting technique that involves obtaining expert opinions through a series of structured questionnaires or interviews.

It is often used in situations where there is a lack of historical data or when the future is uncertain.

The Delphi method is particularly useful when forecasting complex or novel events or when multiple sources of information need to be synthesized.

In contrast, the moving average model, classical decomposition, and simple regression are all quantitative forecasting methods that rely on historical data and statistical analysis to make predictions.

The moving average model uses a rolling average of past data to make predictions, while classical decomposition breaks down a time series into its components (such as trend, seasonality, and irregularity) to model each component separately.

Simple regression, on the other hand, uses a linear equation to model the relationship between two variables and make predictions based on that relationship.

Hence, The Delphi method is not a quantitative forecasting method.

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Anthony's family received $422,848 from the insurance company.

The policy was bought on June 5, 2010 and Anthony passed away on March 22, 2015.

The policy was active for:

= (5 years + 9.5 months)

= 58 months.

The total amount of premiums paid during this time was:

= $1,256/month x 58 months

= $72,848

The face value of the policy was $350,000. The total amount paid out to Anthony's family was:

= $350,000 + $72,848

= $422,848.

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Probability of getting a non-yellow section on the spinner is 75%. The Option A.

Probability deals with finding out likelihood of the occurrence of an event. Its measures chance of an event happening.

We have a total of 8 sections on the spinner, with 2 yellow sections and 6 non-yellow sections.

Number of possibility = 8

Number of sample case= 6 (8 - 6)

The probability of getting a non-yellow section on the spinner is:

P(not yellow) = 6/8

P(not yellow) = 3/4

P(not yellow) = 0.75

P(not yellow) = 75%

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If the $69 cost of electric-toothbrush includes 50% "price-markup", then the cost for the store to purchase it was (d) $46.

Let the cost for the store to purchase the electric toothbrush be = "C".

We know that the "final-price" of the toothbrush, includes the 50% markup, which is = $69,

The price with the 50% markup is calculated by adding 50% of the original cost to the original cost.

So, we have :

⇒ Final price = Original cost + 50% of original cost,

Substituting the value of "final-price" as $69,

We get,

⇒ $69 = C + 0.5C,

⇒ $69 = 1.5C,

⇒ C = $46;

Therefore, the correct option is (d).

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The given question is incomplete, the complete question is

An electric toothbrush costs $69, including a 50% price markup. What was the cost for the store to purchase the electric toothbrush?

(a) $19.00

(b) $23.00

(c) $34.50

(d) $46.00

(a) The books can be arranged in any order ,the answer is 40320 ways.

(b) The mathematics book must be together, and the novels must be together, the answer is 1440 ways.

(c)  The mathematics books must be together, but the other books can be arranged in any order, the answer is 10080 ways.

Further simplify,

a. If the books are to be arranged in any order,

Total number of books = 5 + 2 + 1 = 8

Number of Arrangements = 8!

Number of Arrangements = 8*7*6*5*4*3*2*1

Number of Arrangements = 40320 ways.

b. The mathematics books must be together, and the novels must be together,

To get the number of possible arrangements

First, Calculate the Possible Arrangements of Mathematics Books.

Number of Mathematics Books = 2

Arrangements = 2!

Arrangements = 2*1 = 2

Then, Calculate the Possible Arrangements of Novel Books.

Number of Novel Books = 5

Arrangements = 5!

Arrangements = 5*4*3*2*1

Arrangements = 120

Then Calculate the Possible Arrangements of the Mathematics book bundle, Novel Bundle with Biology book.

The mathematics book bundled together is 1

The novel bundled together is 1

Other books = 1 Biology

Total = 3

Arrangements = 3!

Arrangements = 3*2*1 = 6

Total Arrangements = 2 * 120 * 6

Total Arrangements = 1440

c. If the mathematics book must be together but other books can be arranged in any order.

To get the Number of Possible Arrangements

First, Calculate the Possible Arrangements of Mathematics Books.

Number of Mathematics Books = 2

Arrangements = 2!

Arrangements = 2*1 = 2

Then Calculate the Possible Arrangements of the Mathematics book bundle with other books.

The mathematics book bundled together is 1

Other books = 5 Novels + 1 Biology

Total = 7

Arrangements = 7!

Arrangements = 7*6*5*4*3*2*1

Arrangements = 5040

Total Possible Arrangements = 2 * 5040 = 10080 ways.

(a) The possible arrangements are 403220.

(b) The possible arrangements are 1440.

(c) The possible arrangements are 10080.

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a' is factoring out from the [tex]ax^2+bx[/tex]

The correct option is (2)

Here is the some steps from the question:

Step 1: –c = [tex]ax^2 + bx[/tex]

Step 2: -c = [tex]a[x^2+\frac{b}{ax} ][/tex]

The best explains or justification of step 2:

=> 'a' is taken out common from [tex]ax^2+bx[/tex] .

When we take out 'a' we divide each term by 'a'. so it becomes :

[tex]a[x^2+\frac{b}{ax} ][/tex]

Hence, 'a' is factoring out from the [tex]ax^2+bx[/tex]

So, We can call the 'factoring the binomial'

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The given question is incomplete, complete question is:

A student is deriving the quadratic formula. Her first two steps are shown. Step 1: –c = ax2 + bx Step 2: -c = a[x^2+b/ax] Which best explains or justifies Step 2?

(1) division property of equality

(2) factoring the binomial

(3)completing the square

(4)subtraction property of equality

Here's a sample program in C++ that satisfies your requirements:

```
#include
using namespace std;

int main() {
 int num;
 cout << "Enter an integer between 0 and 35: ";
 cin >> num;

 if (num <= 9) {
   cout << num << endl;
 } else if (num >= 10 && num <= 35) {
   char letter = static_cast('A' + num - 10);
   cout << letter << endl;
 } else {
   cout << "Invalid input." << endl;
 }

 return 0;
}
```

- The program prompts the user to input an integer between 0 and 35 using the `cout` and `cin` statements.
- The `if` statement checks whether the number is less than or equal to 9. If it is, it outputs the number using the `cout` statement.
- The `else if` statement checks whether the number is between 10 and 35 (inclusive). If it is, it calculates the corresponding letter using the ASCII value for 'A' and the given number. The `static_cast` statement converts the calculated value to a character. Finally, the program outputs the letter using the `cout` statement.
- The `else` statement handles the case when the input is outside the range of 0 to 35. It outputs an error message using the `cout` statement.
- The program ends with the `return 0` statement.

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The Jacobian problem requires us to linearize the given nonlinear system about the equilibrium point (0, 0) using the Jacobian and determine its eigenvalues.

To do this, we need to calculate the partial derivatives of the system with respect to x1 and x2 and form the Jacobian matrix. The Jacobian matrix for the given system is: J(x1,x2) = [3x2 3x1+3x2; 0 5], Evaluating the Jacobian matrix at (0,0), we get: J(0,0) = [0 0; 0 5].

To find the eigenvalues of J(0,0), we need to solve the characteristic equation: det(J(0,0)-λI) = 0, where I is the identity matrix. Solving this equation, we get: (0-λ)(5-λ) = 0, which gives us two eigenvalues: λ1 = 0, λ2 = 5

Since one of the eigenvalues is zero, the linearized system is nonlinear. To determine whether the linearized system is stable or unstable, we need to look at the sign of the real part of the eigenvalues. If the real part of all the eigenvalues is negative, then the system is stable, otherwise it is unstable.

In this case, since one of the eigenvalues is zero, the linearized system is not stable. The other eigenvalue is positive, which means that the linearized system is unstable. Therefore, we can conclude that the nonlinear system is also unstable at the equilibrium point (0,0).

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Based on the given data, the height of a plant from Variety A is likely to be closer to the mean. So, correct option is C.

Based on the given data, we can make the following observations:

The mean height of plants from Variety A is 19 inches, while the mean height of plants from Variety B is 13 inches.

The mean absolute deviation (MAD) for Variety A is 1.2 inches, while the MAD for Variety B is 2.4 inches. This means that the heights of plants from Variety A are less variable than the heights of plants from Variety B.

Option A cannot be concluded from the given data as we do not have information on the maximum height of plants from either variety.

Option B cannot be concluded from the given data as there is overlap in the height ranges of the two varieties.

Option C is likely to be true as the MAD for Variety A is smaller, indicating that the heights of plants from this variety are more tightly clustered around the mean of 19 inches.

Option D is unlikely to be true as the MAD for Variety B is larger, indicating that the heights of plants from this variety are more spread out and farther away from the mean of 13 inches.

In conclusion, based on the given data, we can say that the height of a plant from Variety A is likely to be closer to the mean, and the height of a plant from Variety B is likely to be farther away from the mean.

So, correct option is C.

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Let's say the sides of the rectangle are represented by integers a and b. The area of the rectangle is a * b, and the perimeter is 2 * (a + b).

To make a * b equal to 2 * (a + b), we must determine the values of a and b. The equation is rearranged to give us: a * b - 2 * a - 2 * b = 0.

Adding 4 to both sides, we can factorize the left-hand side of the equation using the distributive property: we need to find pairs of integers whose difference is 4. These pairs are:

a - 2 = 4 and b - 2 = 1, which gives a = 6 and b = 3

a - 2 = 2 and b - 2 = 2, which gives a = 4 and b = 4

a - 2 = 1 and b - 2 = 4, which gives a = 3 and b = 6

So the sides of the rectangle could be 6 and 3, 4 and 4, or 3 and 6.

Now we need to find pairs of integers whose difference is 4. These pairs are:

a - 2 = 4 and b - 2 = 1, which gives a = 6 and b = 3

a - 2 = 2 and b - 2 = 2, which gives a = 4 and b = 4

a - 2 = 1 and b - 2 = 4, which gives a = 3 and b = 6

So the sides of the rectangle could be 6 and 3, 4 and 4, or 3 and 6

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In the hypothesis testing, the null and alternative for the claim that mean iq of statistics teachers is greater than 140, are

[tex]H_0 :\mu \leqslant 140[/tex]

[tex]H_a : \mu > 140[/tex]

and the alternative hypothesis is the hypothesis of this claim.

Hypothesis testing in statistics is a process where you to test the results of a survey or experiment based sample to look if you have meaningful results. It is based on hypothesis. The null hypothesis of a test always shows no effect or no relationship between variables, while the alternative hypothesis states your research prediction of an effect or relationship. The null hypothesis is the fact that should be tested and the alternative is everything else.

We have mean iq of statistics teachers is greater than 140. We have to identify the hypothesis for which this claim is true. Now, the null and alternative hypothesis are defined as in this case, [tex]H_0 :\mu ≤ 140[/tex]

[tex]H_a : \mu > 140[/tex]

where μ --> mean iq of statistics

From above, the hypothesis which identify the claim that mean iq of statistics teachers is greater than 140 is alternative hypothesis. Hence, the required answer is alternative hypothesis.

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Mathematically, the claim can be expressed as follows:

µ > 140

where µ represents the population mean IQ score of statistics teachers.

The null hypothesis (H0) is that the population mean IQ score of statistics teachers is not greater than 140:

H0: µ ≤ 140

The alternative hypothesis (Ha) is that the population mean IQ score of statistics teachers is greater than 140:

Ha: µ > 140

Note that the claim corresponds to the alternative hypothesis, Ha.

Null hypothesis (H0): The mean daily attendance at the park is μ = people.

Alternative hypothesis (Ha): The mean daily attendance at the park is not equal to μ ≠ people.

The claim is represented by the alternative hypothesis (Ha), which states that the mean daily attendance at the park is different from the claimed value of people.

Note that the value of μ is not specified in the claim, but it is assumed to be equal to people. The null hypothesis (H0) reflects this assumption, and the alternative hypothesis (Ha) challenges it by stating that the true mean attendance may be different from this value.

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It is proved by both combinatorial argument and algebraic argument that C(2n, 2) = 2 C(n, 2) + n².

The given statement is: C(2n, 2) = 2C(n, 2) + n²

Combinatorial argument:

Suppose we have to choose 2 balls from a bag consists of 2n balls.

So the number of ways to choose that 2 balls = C(2n, 2)

Now in order to do the same thing we take another process. We divide 2n balls in to equal n balls bags. Now we can choose 2 balls in following ways.

(i) 2 balls from first n ball bag and number of ways to do that = C(n, 2).

(ii) 2 balls from second n ball bag and number of ways to do that = C(n, 2) too.

(iii) 1 ball from first n ball bag and another ball from second n balls bag. The number of ways to do this = n*n = n²

So the number of ways to choose 2 balls from 2n balls by dividing the balls in equal two n balls bag is = C(n, 2) + C(n, 2) + n² = 2C(n, 2) + n².

But the event is same just the process to do the work is different so the number of ways to do the work will be equal.

Hence, C(2n, 2) = 2C(n, 2) + n².

Algebraic argument,

We know that C(n, k) = n!/(k!(n - k)!)

So, left hand side is,

C(2n, 2) = 2n!/(2!(2n - 2)!) = 2n(2n - 1)/2 = 2n² - n.

The right hand side is,

2C(n, 2) + n² = 2n!/(2!(n - 2)!) + n² = n(n - 1) + n² = 2n² - n.

Since Left Hand Side = Right Hand Side. So the statement is true by algebraic way too.

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A sample of 2400 adults in Ohio would be needed to guarantee that the standard deviation of the proportion who support the increase in the state sales tax (p^) is no more than 0.01.

To determine the sample size needed to guarantee that the standard deviation of p^ is no more than 0.01, we need to use the formula:

n = (Zα/2)^2 * p(1-p) / (d^2)

where n is the sample size, Zα/2 is the critical value of the standard normal distribution for a confidence level of α/2, p is the proportion of adults in Ohio who support the increase (0.4 in this case), and d is the maximum margin of error (0.01 in this case).

Assuming a 95% confidence level (α = 0.05), the critical value of Zα/2 is 1.96. Substituting these values into the formula, we get:

n = (1.96)^2 * 0.4(1-0.4) / (0.01)^2
n = 1536.16

Therefore, we would need a sample size of at least 1537 adults in Ohio to guarantee that the standard deviation of p^ is no more than 0.01.
To calculate the required sample size for a given standard deviation of the sample proportion (p^), we can use the formula:

σ(p^) = √(pq/n)

where σ(p^) is the desired standard deviation, p is the proportion of support (0.40), q is the proportion of non-support (1-p, which is 0.60), and n is the sample size.

We want to guarantee that the standard deviation of p^ is no more than 0.01. Therefore, we set σ(p^) to be 0.01:

0.01 = √(0.40 * 0.60 / n)

Squaring both sides:

0.0001 = 0.24 / n

Now, solve for n:

n = 0.24 / 0.0001

n = 2400

So, a sample of 2400 adults in Ohio would be needed to guarantee that the standard deviation of the proportion who support the increase in the state sales tax (p^) is no more than 0.01.

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The probability that more boys than girls are chosen is approximately 39.67%.

To determine the probability that more boys than girls are chosen from a classroom with 10 boys and 12 girls, we need to consider the possible ways this can happen. There are two scenarios:

1. 3 boys and 2 girls are chosen.
2. 4 boys and 1 girl are chosen.

First, calculate the total number of ways to choose 5 students from 22 (10 boys + 12 girls) using the combination formula: C(n, k) = n! / (k! * (n-k)!)

C(22, 5) = 22! / (5! * 17!) = 26,334

Now, calculate the probabilities for the two scenarios:

1. 3 boys and 2 girls are chosen:
C(10, 3) = 10! / (3! * 7!) = 120
C(12, 2) = 12! / (2! * 10!) = 66
Total combinations: 120 * 66 = 7,920

2. 4 boys and 1 girl are chosen:
C(10, 4) = 10! / (4! * 6!) = 210
C(12, 1) = 12! / (1! * 11!) = 12
Total combinations: 210 * 12 = 2,520

Add the combinations for both scenarios: 7,920 + 2,520 = 10,440

Now, calculate the probability:

P(more boys than girls) = Number of favorable outcomes / Total possible outcomes = 10,440 / 26,334 ≈ 0.3967 or 39.67%

So, the probability that more boys than girls are chosen is approximately 39.67%.

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The term that refers to the strength of association between variables is b) effect size. Effect size is a quantitative measure that describes the magnitude of the relationship between two or more variables. It is particularly useful in comparing the results of different studies or experiments, as it provides a standardized measure of the strength of the association, regardless of the specific context or sample size.

In contrast, a) statistical index is a broader term that refers to any statistic used to measure a particular characteristic or attribute, such as the mean or median. c) Standard deviation is a measure of the dispersion or spread of data points around the mean, and while it may provide some context for the strength of the relationship, it does not directly measure the association between variables. d) Linear degree refers to the degree of a linear equation, which is unrelated to the strength of association between variables.

In summary, effect size is the most appropriate term to describe the strength of association between variables, as it provides a standardized measure of the magnitude of the relationship that can be used to compare different studies or experiments. It is an important concept in research and data analysis, as it allows researchers to understand the practical significance of their findings and make informed decisions about their work.

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In a right triangle, one of the interior angles measures exactly 90 degrees, which is called the right angle.

This right angle is formed by the intersection of the two non-hypotenuse sides of the triangle, and it is located at the vertex where these sides meet. The "right angle vertex" or "vertex of the right angle" are other names for this vertex. The right angle vertex is an important feature of right triangles, and it is used in many geometric and trigonometric calculations. For example, the Pythagorean Theorem, which relates the lengths of the sides of a right triangle, depends on the location of the right angle vertex.

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The probability of a grand piano selling for more than $67,400 is approximately 0.3819

To solve this problem, we need to standardize the given value using the mean and standard deviation and then find the area under the standard normal distribution curve corresponding to the standardized value.

We can use the Z-score formula to standardize the value:

Z = (X - μ) / σ

where X is the sale price, μ is the mean, and σ is the standard deviation.

Substituting the given values, we get:

Z = (67,400 - 66,000) / 4,600

Z = 0.3043

Using a standard normal distribution table or calculator, we can find the area under the curve to the right of Z = 0.3043. The probability of a grand piano selling for more than $67,400 is the same as the probability of a standard normal variable being greater than 0.3043.

From the standard normal distribution table, we find that the area to the right of Z = 0.3043 is approximately 0.3819.

Therefore, the probability of a grand piano selling for more than $67,400 is approximately 0.3819 or 38.19%.

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Answer:

(D) a two sample t -test for means

To determine if there is a significant difference in the average test score of talkative and quiet children at the age of 24 months, a two-sample t-test should be used.

To determine if there is a significant difference in the average test score of talkative and quiet children at the age of 24 months, you should use an Independent Two-Sample T-test. This test is appropriate because it compares the means of two independent groups (talkative and quiet) and the samples are simple random samples with the other conditions for inference being met. Here's a step-by-step explanation:

1. State the null and alternative hypotheses:
  H0 (null hypothesis): There is no significant difference in the average test score of talkative and quiet children (µ1 - µ2 = 0)
  Ha (alternative hypothesis): There is a significant difference in the average test score of talkative and quiet children (µ1 - µ2 ≠ 0)

2. Calculate the sample means, sample standard deviations, and sample sizes for each group.

3. Calculate the test statistic (T-value) using the formula:
  T = (M1 - M2) / sqrt((SD1² / n1) + (SD2² / n2))

4. Determine the degrees of freedom (df) using the formula:
  df = min(n1 - 1, n2 - 1)

5. Find the critical T-value from the T-distribution table for the given level of significance (e.g., α = 0.05) and the calculated degrees of freedom.

6. Compare the calculated T-value to the critical T-value:
  - If the calculated T-value is greater than or equal to the critical T-value, reject the null hypothesis.
  - If the calculated T-value is less than the critical T-value, fail to reject the null hypothesis.

7. Interpret the results in the context of the study, which is the relationship between language skills, mental development, and talkative/quiet children at the age of 24 months.

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