Billy's age is twice Joe's age and the sum of their ages is 45. How old is Billy?

Answer:

1) [tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]

2) [tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]

3) [tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]

And the variance would be given by:

[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]

4) [tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]

And the variance would be given by:

[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]

Step-by-step explanation:

For this case we have the following distributions given:

Probability  M   J

0.3           14%  22%

0.4           10%    4%

0.3           19%    12%

Part 1

The expected value is given by this formula:

[tex] E(X)=\sum_{i=1}^n X_i P(X_i)[/tex]

And replacing we got:

[tex] E(M) = 14*0.3 + 10*0.4 + 19*0.3 = 13.9 \%[/tex]

Part 2

[tex]E(J)= 22*0.3 + 4*0.4 + 12*0.3 = 11.8 \%[/tex]

Part 3

We can calculate the second moment first with the following formula:

[tex] E(M^2) = 14^2*0.3 + 10^2*0.4 + 19^2*0.3 = 207.1 [/tex]

And the variance would be given by:

[tex]Var (M)= E(M^2) -[E(M)]^2 = 207.1 -(13.9^2)= 13.89[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{13.89}= 3.73[/tex]

Part 4

We can calculate the second moment first with the following formula:

[tex] E(J^2) = 22^2*0.3 + 4^2*0.4 + 12^2*0.3 =194.8 [/tex]

And the variance would be given by:

[tex]Var (J)= E(J^2) -[E(J)]^2 = 194.8 -(11.8^2)= 55.56[/tex]

And the deviation would be:

[tex] Sd(M) = \sqrt{55.56}= 7.45[/tex]

Answer:

(a)[tex]\dfrac{2}{13}[/tex]

(b)[tex]\dfrac{3}{13}[/tex]

(c)[tex]\dfrac{4}{13}[/tex]

Step-by-step explanation:

In a standard deck, there are 52 cards which are divided into 4 suits.

(a)

Number of Seven Cards =4

Number of King cards =4

Probability of randomly selecting a seven or king

=P(Seven)+P(King)

[tex]=\dfrac{4}{52} +\dfrac{4}{52} \\=\dfrac{8}{52}\\=\dfrac{2}{13}[/tex]

(b)

Number of Seven Cards =4

Number of King cards =4

Number of Jack(J) cards =4

Probability of randomly selecting a seven or king

=P(Seven)+P(King)+P(Jack)

[tex]=\dfrac{4}{52} +\dfrac{4}{52}+\dfrac{4}{52} \\=\dfrac{12}{52}\\=\dfrac{3}{13}[/tex]

(c)

Number of Queen Cards =4

Number of Spade cards =13

Number of Queen and Spade cards =1

Probability of randomly selecting a seven or king

[tex]=P$(Queen)+P(Spade)-P(Queen and Spade Card)\\=\dfrac{4}{52} +\dfrac{13}{52} -\dfrac{1}{52} \\=\dfrac{16}{52} \\=\dfrac{4}{13}[/tex]

Answer:

-The total area of a Rectangular Prism:

[tex]A = 366[/tex] [tex]in^{2}[/tex]

Step-by-step explanation:

-To find the total area of a rectangular prism, you need this formula:

[tex]A = 2(l \cdot w + l \cdot h + w \cdot h)[/tex]

[tex]l =[/tex] Length

[tex]w =[/tex] Width

[tex]h =[/tex] Height

-Apply the length, width and height for the formula:

[tex]A = 2(11 \cdot 8 + 11 \cdot 5 + 8 \cdot 5)[/tex]

[tex]l =[/tex] 11 in

[tex]w =[/tex] 8 in

[tex]h =[/tex] 5 in

-Then, solve for the area:

[tex]A = 2(11 \cdot 8 + 11 \cdot 5 + 8 \cdot 5)[/tex]

[tex]A = 2(88 + 55 + 40)[/tex]

[tex]A = 2(143 + 40)[/tex]

[tex]A = 2 \times 183[/tex]

[tex]A = 366[/tex]

So, the total area would be [tex]366[/tex] [tex]in ^{2}[/tex].

Answer:

Step-by-step explanation:

REcall that given a set A, * is a equivalence relation over A if

- for a in A, then a*a.

- for a,b in A. If a*b, then b*a.

- for a,b,c in A. If a*b and b*c then a*c.

Consider A the set of all ordered pairs of positive integers.

- Let (a,b) in A. Then a+b = a+b. So, by definition (a,b)R(a,b).

- Let (a,b), (c,d) in A and suppose that (a,b)R(c,d) . Then, by definition a+d = b+c. Since the + is commutative over the integers, this implies that d+a = c+b. Then (c,d)R(a,b).

- Let (a,b),(c,d), (e,f) in A and suppose that (a,b)R(c,d) and (c,d)R(e,f). Then

a+d = b+c, c+f = d+e.  We have that f = d+e-c. So a+f = a+d+e-c. From the first equation we find that a+d-c = b. Then a+f = b+e. So, by definition (a,b)R(e,f).

So R is an equivalence relation.

[(a,b)] is the equivalence class of (a,b). This is by definition, finding all the elements of A that are equivalente to (a,b).

Let us find all the possible elements of A that are equivalent to (2,4). Let (a,b)R(2,4) Then a+4 = b+2. This implies that a+2 = b. So all the elements of the form (a,a+2) are part of this class.

Answer: -6m-n+3

Step-by-step explanation:

The answer is -6m-n+3 because -3

times 2m is -6m and -n stays the same its outside of the parenthesis

and lastly -3 times -1 is positive 3

so answer maches up with the last one

the answer is -6m-n+3

Hope this helps :)

Answer:

-6m-n+3

Step-by-step explanation:

-3 x 2 is -6m (n stays same)

-3 x -1 is whole or positive 3

put it together and u get -6m-n+3

hope this helps

Answer:

Dear Laura Ramirez

Answer to your query is provided below

1) option A is correct

2) option B is correct

Step-by-step explanation:

Explanation for the first question attached in image

Also note - The converse of the hinge theorem states that if two triangles have two congruent sides, then the triangle with the longer third side will have a larger angle opposite that third side.

Answer:

1) option A is correct2) option B is correct

Step-by-step explanation:

Answer:

answer for the question is 130 length

Answer: No.

Step-by-step explanation:

I guess that here we have the statement:

If the sum of two numbers is odd----> can their quotient be an odd number?

first, for n an integer number, we have that:

an odd number can be written as 2n + 1

an even number can be written as 2n.

The sum of two numbers is only odd if one of them is odd and the other even.

Then we have a number that is 2n and other that is 2k + 1, for n and k integer numbers.

Now, let's see if the quotient can also be an odd number.

One way to think this is:

There is an odd number such that when we multiply it by another odd number, the result is an even number?

no, and i can prove it as:

let 2k + 1 be an odd number, and 2j + 1 other.

the product is:

(2k + 1)*(2j + 1) = 2*(2*k*j + k + j) + 1

and as k and j are integers, also does 2*k*j + k + j, so:

2*(2*k*j + k + j) + 1 is an odd number.

This says that the product of two odd numbers is always odd, then we never can have that the quotient between an even number and an odd number is odd.

Answer: 2

Step-by-step explanation:

9 × 2 - 16

18 - 16

2

-4y ≤ -12

Divide both sides by -4:

y ≤ 3

Because both sides were divided by a negative value you need to reverse the inequality sign:

y ≥ 3

Answer:

y = 3

Step-by-step explanation:

it says -4y ≤ -12 sooooooo    4 x 3 = 12!!!! so y = 3

Answer:

655 people would need to be surveyed.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.

[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

In which

z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].

In this question, we have that:

[tex]\pi = 0.68[/tex]

The margin of error is:

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

90% confidence level

So [tex]\alpha = 0.1[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.1}{2} = 0.95[/tex], so [tex]Z = 1.645[/tex].

How many people would need to be surveyed for a 90% confidence interval to ensure the margin of error would be less than 3%?

We need to survey n adults.

n is found when M = 0.03. So

[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]

[tex]0.03 = 1.645\sqrt{\frac{0.68*0.32}{n}}[/tex]

[tex]0.03\sqrt{n} = 1.645\sqrt{0.68*0.32}[/tex]

[tex]\sqrt{n} = \frac{1.645\sqrt{0.68*0.32}}{0.03}[/tex]

[tex](\sqrt{n})^{2} = (\frac{1.645\sqrt{0.68*0.32}}{0.03})^{2}[/tex]

[tex]n = 654.3[/tex]

Rounding up

655 people would need to be surveyed.

Answer:

C

Step-by-step explanation:

Given

x + 10 = 3(x - 1)² ← expand (x - 1)² using FOIL

x + 10 = 3(x² - 2x + 1) ← distribute

x + 10 = 3x² - 6x + 3 ← subtract x + 10 from both sides

0 = 3x² - 7x - 7 → C

Answer:

Step-by-step explanation:

Answer:

8/3

Step-by-step explanation:

6(x-2)=4

x-2=4/6

x= 8/3

Answer:

x = 8/3

Step-by-step explanation:

Use Distributive Property

6(x-2) = 4

6x -12 = 4

add 12 on both sides

6x = 16

Divide by 6

x = 8/3

In decimal form: 2.667

Answer:

Test statistic t = 5.25

P-value = 0.000002 (one-tailed test)

Step-by-step explanation:

This is a hypothesis test for the population mean.

The claim is that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

Then, the null and alternative hypothesis are:

[tex]H_0: \mu=7\\\\H_a:\mu> 7[/tex]

The significance level is 0.05.

The sample has a size n=49.

The sample mean is M=8.5.

As the standard deviation of the population is not known, we estimate it with the sample standard deviation, that has a value of s=√s^2=√4=2.

The estimated standard error of the mean is computed using the formula:

[tex]s_M=\dfrac{s}{\sqrt{n}}=\dfrac{2}{\sqrt{49}}=0.29[/tex]

Then, we can calculate the t-statistic as:

[tex]t=\dfrac{M-\mu}{s/\sqrt{n}}=\dfrac{8.5-7}{0.29}=\dfrac{1.5}{0.29}=5.25[/tex]

The degrees of freedom for this sample size are:

[tex]df=n-1=49-1=48[/tex]

This test is a right-tailed test, with 48 degrees of freedom and t=5.25, so the P-value for this test is calculated as (using a t-table):

[tex]\text{P-value}=P(t>5.25)=0.000002[/tex]

As the P-value (0.000002) is smaller than the significance level (0.05), the effect is significant.

The null hypothesis is rejected.

There is enough evidence to support the claim that the average amount of time that a freshman at TAMU studies is significantly higher than 7 hours.

Answer: A (30)

Step-by-step explanation:

By defaults, data will be enabled in tens. And it increases by replicating the initial value.

There is no way the maximum number of dataflow definitions available in this situation will be 45, 25 or 35

The only possible replicant that can be available is 30

Answer:

40 litres

Step-by-step explanation:

V = l x w x h

50 x 40 x 20 = 40000

40000 cm^3

1cm^3 = 1ml

40000 cm^3/ 1cm^3 = 40000ml

40000 x 10^-3 = 40 litres

Answer:

16.67% probability of getting 2 blues

Step-by-step explanation:

A probability is the number of desired outcomes divided by the number of total outcomes.

The order in which the marbles are selected is not important. So we use the combinations formula to solve this question.

Combinations formula:

[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.

[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]

What is the probability of getting 2 blues?

Desired outcomes:

Two blue marbles, from a set of 4.

[tex]D = C_{4,2} = \frac{4!}{2!(4-2)!} = 6[/tex]

Total outcomes:

Two marbles, from a set of 9.

[tex]T = C_{9,2} = \frac{9!}{2!(9-2)!} = 36[/tex]

Probability:

[tex]p = \frac{D}{T} = \frac{6}{36} = 0.1667[/tex]

16.67% probability of getting 2 blues

Answer:

answer d) 20

Step-by-step explanation:

Because the two lines are parallel two by two, the figure is a parallelogram.

In a parallelogram the opposite corners are identical.

Given:

opposite corner1 = 130°

opposite corner2= (6a + 10)°

Because corner1 = corner2 we now have:

(6a + 10) = 130

6a + 0 = 130 -10

6a = 120

a = 20

Which is answer d).

Answer:

4 - 7 = -3

-3 / 3 = -1

Answer:

Step-by-step explanation:

it is -12 because -6 plus -6 is also like 6 plus 6

and then you have to add the negative Sign.

pls brainliest me

-6 - 6 = - 12

Happy to help! Please mark as the brainliest!

easy claps!!

Answer: 30=2x+4 and there are 17 girls in the class.

Step-by-step explanation: if x+4=[total girls] and x=[total boys] and 30=[total kids], then x+4+x = 2x+4 = [total kids], since total kids id 30 then our equation is 30 = 2x + 4 and x= 13boys so 30-13= 17girls.

It's BASIC prealgebra so you should probably practice bit more with linear equations!

Answer:

C............PAC-MAN

Step-by-step explanation:

Answer:

Car: 60%

Motorcycle: 30%

Truck: 10%

Step-by-step explanation:

Car: [tex]\frac{12}{12+6+2} =\frac{12}{20} =\frac{60}{100}[/tex] or 60%

Motorcycle: [tex]\frac{6}{12+6+2} =\frac{6}{20} =\frac{30}{100}[/tex] or 30%

Truck: [tex]\frac{2}{12+6+2} =\frac{2}{20} =\frac{10}{100}[/tex] or 10%

Answer:

(a) The probability that all five have used a computer while under the influence of alcohol is 0.0021.

(b) The probability that at least one has not used a computer while under the influence of alcohol is 0.9979.

(c) The probability that none of the five have used a computer while under the influence of alcohol is 0.1804.

(d) The probability that at least one has used a computer while under the influence of alcohol is 0.8196.

Step-by-step explanation:

We are given that among 25- to 30-year-olds, 29% say they have used a computer while under the influence of alcohol.

Suppose five 25- to 30-year-olds are selected at random.

The above situation can be represented through the binomial distribution;

[tex]P(X = x) = \binom{n}{r}\times p^{r} \times (1-p)^{n-r} ; x = 0,1,2,3,.........[/tex]

where, n = number of trials (samples) taken = Five 25- to 30-year-olds

            r = number of success

            p = probability of success which in our question is probability that

                  people used a computer while under the influence of alcohol,

                   i.e. p = 29%.

Let X = Number of people who used computer while under the influence of alcohol.

So, X ~ Binom(n = 5, p = 0.29)

(a) The probability that all five have used a computer while under the influence of alcohol is given by = P(X = 5)

               P(X = 5)  =  [tex]\binom{5}{5}\times 0.29^{5} \times (1-0.29)^{5-5}[/tex]

                              =  [tex]1 \times 0.29^{5} \times 0.71^{0}[/tex]

                              =  0.0021

(b) The probability that at least one has not used a computer while under the influence of alcohol is given by = P(X [tex]\geq[/tex] 1)

Here, the probability of success (p) will change because now the success for us is that people have not used a computer while under the influence of alcohol = 1 - 0.29 = 0.71

SO, now X ~ Binom(n = 5, p = 0.71)

               P(X [tex]\geq[/tex] 1)  =  1 - P(X = 0)   

                              =  [tex]1-\binom{5}{0}\times 0.71^{0} \times (1-0.71)^{5-0}[/tex]

                              =  [tex]1 -(1 \times 1 \times 0.29^{5})[/tex]

                              =  1 - 0.0021 = 0.9979.

(c) The probability that none of the five have used a computer while under the influence of alcohol is given by = P(X = 0)

               P(X = 0)  =  [tex]\binom{5}{0}\times 0.29^{0} \times (1-0.29)^{5-0}[/tex]

                              =  [tex]1 \times 1 \times 0.71^{5}[/tex]

                              =  0.1804

(d) The probability that at least one has used a computer while under the influence of alcohol is given by = P(X [tex]\geq[/tex] 1)

               P(X [tex]\geq[/tex] 1)  =  1 - P(X = 0)   

                              =  [tex]1-\binom{5}{0}\times 0.29^{0} \times (1-0.29)^{5-0}[/tex]

                              =  [tex]1 -(1 \times 1 \times 0.71^{5})[/tex]

                              =  1 - 0.1804 = 0.8196

Answer:

E. 400

Step-by-step explanation:

So this is how we set this up, and how we solve

[tex]0.25x=100\\x=100/0.25\\x=400[/tex]

Hope this helps!

So you are solving for circumference of a quarter circle: [tex]\frac{1}{4}2 \pi r[/tex]

r= 28

[tex]\pi=3.14[/tex]

[tex]\frac{1}{4}2(87.92)=\\43.96[/tex]

Answer:

ofn

Step-by-step explanation:

Answer:

Step-by-step explanation:

Since there are 44 average people out of 80. We can do this,

Total students : 600

Checked: 80

Average: 44

Number of averaged throughout the school: 600/80 * 44

                                                                        l: 7.5 * 44

Thus it is: 330 average students

Answer:

Step-by-step explanation:

Confidence interval for the difference in the two proportions is written as

Difference in sample proportions ± margin of error

Sample proportion, p= x/n

Where x = number of success

n = number of samples

For the first brochure,

x = 100

n1 = 500

p1 = 100/500 = 0.2

For the second brochure

x = 125

n2 = 500

p2 = 125/500 = 0.25

Margin of error = z√[p1(1 - p1)/n1 + p2(1 - p2)/n2]

To determine the z score, we subtract the confidence level from 100% to get α

α = 1 - 0.95 = 0.05

α/2 = 0.05/2 = 0.025

This is the area in each tail. Since we want the area in the middle, it becomes

1 - 0.025 = 0.975

The z score corresponding to the area on the z table is 1.96. Thus, the z score for confidence level of 95% is 1.96

Margin of error = 1.96 × √[0.2(1 - 0.2)/500 + 0.25(1 - 0.25)/500]

= 1.96 × √0.000695

= 0.052

Confidence interval = (0.2 - 0.25) ± 0.052

= - 0.05 ± 0.052

Answer:

The correct option is (A).

Step-by-step explanation:

If the reduced row echelon form of the coefficient matrix of a linear system of equations in four different variables has a pivot, i.e. 1, in each column, then the reduced row echelon form of the coefficient matrix is say A is an identity matrix, here I₄, since there are 4 variables.

[tex]\left[\begin{array}{cccc}1&0&0&0\\0&1&0&0\\0&0&1&0\\0&0&0&1\end{array}\right][/tex]

Then the corresponding augmented matrix [ A|B] , where the matrix is the representation of the linear system is AX = B, must be:

[tex]\left[\begin{array}{ccccc}1&0&0&0&a\\0&1&0&0&b\\0&0&1&0&c\\0&0&0&1&d\end{array}\right][/tex]

Now the given linear system is consistent as the right most column of the augmented matrix is a linear combination of the columns of A as the reduced row echelon form of A has a pivot in each column.

Thus, the correct option is (A).

Answer:

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.

Step-by-step explanation:

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the zscore of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

In this question:

[tex]\mu = 152, \sigma = 14.5[/tex]

The z-score when x=187 is ...

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

[tex]Z = \frac{187 - 152}{14.5}[/tex]

[tex]Z = 2.41[/tex]

The z-score when x=187 is 2.41. The mean is 187. This z-score tells you that x = 187 is 2.41 standard deviations above the mean.