Answer:
Ten minutes.
Hope that helps!
Mrs. Baker found 25 shells on the beach. She brought 2/5 of the shells to her
classroom. The rest of the shells she set on a bookshelf at her house. How many
shells did she bring to schoof? How many shells are at her house? (Show your work
on another sheet of paper if necessary.)
Answer:
A. 10 B. 15
Step-by-step explanation:
A. 25/1 * 2/5= 50/5
reduced it is 10
B. 25-10=15
Answer:
she brought 10 shells to her classroom and 15 shells to her house. Hope that helps!
) The National Assessment of Educational Progress (NAEP) gave a test of basic arithmetic and the ability to apply it in everyday life to a sample of 840 men 21 to 25 years of age. Scores range from 0 to 500; for example, someone with a score of 325 can determine the price of a meal from a menu. The mean score for these 840 young men was x⎯⎯⎯ = 272. We want to estimate the mean score μ in the population of all young men. Consider the NAEP sample as an SRS from a Normal population with standard deviation σ = 60. (a) If we take many samples, the sample mean x⎯⎯⎯ varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score μ in the population. What is the standard deviation of this sampling distribution? (b) According to the 95 part of the 68-95-99.7 rule, 95% of all values of x⎯⎯⎯ fall within _______ on either side of the unknown mean μ. What is the missing number? (c) What is the 95% confidence interval for the population mean score μ based on this one sample? Note: Use the 68-95-99.7 rule to find the interval.
Answer:
a) The standard deviation of this sampling distribution is 2.07.
b) The missing number is 4.14.
c) The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.
Step-by-step explanation:
To solve this question, we need to understand the Empirical Rule and the Central Limit Theorem.
Empirical Rule:
The Empirical Rule states that, for a normally distributed random variable:
68% of the measures are within 1 standard deviation of the mean.
95% of the measures are within 2 standard deviation of the mean.
99.7% of the measures are within 3 standard deviations of the mean.
Central Limit Theorem:
The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean [tex]\mu[/tex] and standard deviation [tex]s = \frac{\sigma}{\sqrt{n}}[/tex].
For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.
In this question:
[tex]\mu = 272, n = 840, \sigma = 60[/tex]
(a) If we take many samples, the sample mean x⎯⎯⎯ varies from sample to sample according to a Normal distribution with mean equal to the unknown mean score μ in the population. What is the standard deviation of this sampling distribution?
Using the Central Limit Theorem:
[tex]s = \frac{\sigma}{\sqrt{n}} = \frac{60}{\sqrt{840}} = 2.07[/tex]
The standard deviation of this sampling distribution is 2.07.
(b) According to the 95 part of the 68-95-99.7 rule, 95% of all values of x⎯⎯⎯ fall within _______ on either side of the unknown mean μ. What is the missing number?
Within 2 standard deviations of the mean.
So, 2*2.07 = 4.14
The missing number is 4.14.
(c) What is the 95% confidence interval for the population mean score μ based on this one sample?
Within 4.14 of the mean
272 - 4.14 = 267.86
272 + 4.14 = 276.14
The 95% confidence interval for the population mean score μ based on this one sample is between 267.86 and 276.14.
Consider the expressions 3x(x − 2) + 2 and 2x2 + 3x − 18.
Part 1 out of 2
Evaluate each expression for x = 4 and for x = 5. Based on your results, do you know whether the two expressions are equivalent? Complete the explanation.
For x = 4, each expression has a value of
26
. For x = 5, each expression has a value of
. These results suggest that the expressions
(select)
equivalent, but
(select)
the expressions are equivalent.
Answer:
See answer below
Step-by-step explanation:
For the first expression
3 x (x - 2) + 2 = 3 x^2 - 6 x + 2
evaluated at x= 4 we get: 26
and for x = 5 we get 47.
For the second expression
2 x^2 + 3 x - 18
we get the exact same values when doing the evaluation at these two points.
Based on those results, one may think the expressions may be equivalent, but they are not equivalent. Because at any other x-value, their results are different. See for example that for x = 0 the first one gives "2" while the second one gives -18.
what is 9+2 I WILL MARK BRAINIEST
Answer:
11 ! have a great dayy:) !
The function f(x) = 400 * (1.2) ^ x models a population of mice after x years. What will the population be in 7 years ?
Answer:
Step-by-step explanation:
400×1.2⁷ ≅ 1433 mice
y + 5 = (x + 3)
slope (m): ?
coordinates: ?
Answer:
Your slope would be: -5
Step-by-step explanation:
First we need to format it into a linear equation which is: y= mx+b
y+5= (x+3)
and than minus 5 on each side to get:
y=(x+3)-5
than use distributive property to get:
y= -5x+-15
your slope would be:
-5
and than you can get any coordinates from the line if you graph the line on the site "desmos" so just use that site :)
hope it helps!
20 points for this question
Answer:
Step-by-step explanation:jk
Answer:
10
Step-by-step explanation:
I need help finding the answer to this:
Nathan opens a new savings account and makes an initial deposit of $400. If the account earns 2% annual interest, how much interest will he earn in 9 months?
Answer:
He will earn $6 in interest in 9 months.
Step-by-step explanation:
This is a simple interest problem.
The simple interest formula is given by:
[tex]E = P*I*t[/tex]
In which E is the amount of interest earned, P is the principal(the initial amount of money), I is the interest rate(yearly, as a decimal) and t is the time.
After t years, the total amount of money is:
[tex]T = E + P[/tex]
Initial deposit of $400.
This means that [tex]P = 400[/tex]
2% annual interest
This means that [tex]I = 0.02[/tex]
How much interest will he earn in 9 months?
An year has 12 months, this means that [tex]t = \frac{9}{12} = \frac{3}{4} = 0.75[/tex]
This is E. So
[tex]E = P*I*t = 400*0.02*0.75 = 6[/tex]
He will earn $6 in interest in 9 months.
Model the problem with algebra tiles. Then use the model to write an algebraic expression that represents the situation.
Cammie ran three times as far.
The situation can be modeled with algebra tiles by
________.
The situation can be represented as an algebraic expression as
______.
Answer:
Model the problem with algebra tiles. Then use the model to write an algebraic expression that represents the situation.
Cammie ran three times as far.
The situation can be modeled with algebra tiles by
✔ three orange x tiles
.
The situation can be represented as an algebraic expression as
✔ 3x
.
Step-by-step explanation:
Hope this helps!!
ig- crochetsbyandrea
Answer:
1 three orange x tiles
2 3x
Step-by-step explanation:
What is the integer?
Sally lost 40 dimes because she did not put the money in her piggy bank.
Answer:
-40
Step-by-step explanation:
This is because she LOST 40 dimes making it a negative number, so the integer to represent this would be -40.
PLEASE HELP
Betty has a piece of ribbon that is 33 feet. How can she cut it into pieces without
wasting any? Select all that apply.
A. She can cut 4 pieces that are 8.25 feet each.
LA
B. She can cut 5 pieces that are 6.6 feet each.
ock
C. She can cut 4 pieces that are 8 feet each.
4
-
D. She can cut 5 pieces that are 6.75 feet each.
Answer:
Step-by-step explanation:
A. She can cut 4 pieces that are 8.25 feet each. This uses all 33 feet of ribbon with no waste.
B. She can cut 5 pieces that are 6.6 feet each. This uses all 33 feet of ribbon with no waste.
C. She can cut 4 pieces that are 8 feet each. This adds up to 32 feet, and so 1 ft is wasted
D. She can cut 5 pieces that are 6.75 feet each. Not possible, as this adds up to 33.75 ft, which is more ribbon than Betty has.
pleaseeeee help (15 points)
Answer:
Step-by-step explanation:
what are the vocabulary words that u are supposed to use?
11.45 x 3.7 =
(step by step explanation pls)
A ramp is propped against the back of a truck. There is a 30 degree
angle between the ramp and the horizontal pavement
If the distance along the ground from the end of the ramp to the point
on the ground below the back of the truck is 9 feet, how long is the
ramp, in feet? Round your answer to the nearest whole number,
Step-by-step explanation:
hope it help:)
/////////////////////
The trigonometric function gives the ratio of different sides of a right-angle triangle. The length of the ramp is equal to 10ft.
What are Trigonometric functions?The trigonometric function gives the ratio of different sides of a right-angle triangle.
[tex]\rm Sin \theta=\dfrac{Perpendicular}{Hypotenuse}\\\\\\Cos \theta=\dfrac{Base}{Hypotenuse}\\\\\\Tan \theta=\dfrac{Perpendicular}{Base}[/tex]
where perpendicular is the side of the triangle which is opposite to the angle, and the hypotenuse is the longest side of the triangle which is opposite to the 90° angle.
The length of the ramp is,
Cos(θ) = Base/Hypotenuse
Cos(30°) = 9ft /The length of the ramp
The length of the ramp = 9ft/Cos(30°)
Length of the ramp = 10.3923 ft ≈ 10ft
Hence, the length of the ramp is equal to 10ft.
Learn more about Trigonometric functions:
https://brainly.com/question/6904750
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Give an example of a radical with two answers. Then solve your example. with give brainliest ong
Wilbert needs a student loan to finish school. He needs $4200 and has two options.
Option A: 4 years at 4.5% interest with monthly payments of $95.77
Option B: 3 years at 4.7% interest with monthly payments of $125.31
Which loan should Wilbert choose and how much will Wilbert save with that loan?
First, calculate the total payback on each loan.
Answer:
A) 4596.96
B) 4511.16
Step-by-step explanation:
Wilbert should choose option B. The savings will be $85.8 for the loan.
What is the loan amount?The sum you borrow to purchase the home is known as the amount borrowed. Because most lenders don't always offer 100% financing, it usually differs from the purchase price.
It's also crucial to take the loan-to-value ratio into account. Lenders frequently discuss this value, which compared the loan amount with the purchase price.
Checking for 4 years at 4.5% interest with monthly payments of $95.77
4596.96-4200=396.96
Checking for 3 years at 4.7% interest with monthly payments of $125.31
396.96-311.16=85.8
Therefore, Wilbert should choose option B. The savings will be $85.8 for the loan.
To know more about the Loan amount follow
https://brainly.com/question/26011426
#SPJ5
Travelling with a current, a boat covers a distance 1.5times greater than travelling against the current in the same amount of time. What is the speed of the boat in still water if the speed of the current is 1.5 mph
An array of 30 LED bulbs is used in an automotive light. The probability that a bulb is defective is 0.001 and defective bulbs occur independently. Determine the following: a. Probability that an automotive light has two or more defective bulbs. b. Expected number of automotive lights to check to obtain one with two or more defective bulbs.
Answer:
a) 0.0005 = 0.05% probability that an automotive light has two or more defective bulbs.
b) 4000 automotive lights.
Step-by-step explanation:
For each LED, there are only two possible outcomes. Either it is defective, or it is not. Defective bulbs occur independently, which means that we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
In which [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]
And p is the probability of X happening.
An array of 30 LED bulbs is used in an automotive light. The probability that a bulb is defective is 0.001.
This means that, respectively, [tex]n = 30, p = 0.001[/tex].
a. Probability that an automotive light has two or more defective bulbs.
This is:
[tex]P(X \geq 2) = 1 - P(X < 2)[/tex]
In which
[tex]P(X < 2) = P(X = 0) + P(X = 1)[/tex]
So
[tex]P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}[/tex]
[tex]P(X = 0) = C_{30,0}.(0.001)^{0}.(0.999)^{30} = 0.9704[/tex]
[tex]P(X = 1) = C_{30,1}.(0.001)^{1}.(0.999)^{29} = 0.0291[/tex]
[tex]P(X < 2) = P(X = 0) + P(X = 1) = 0.9704 + 0.0291 = 0.9995[/tex]
[tex]P(X \geq 2) = 1 - P(X < 2) = 1 - 0.9995 = 0.0005[/tex]
0.0005 = 0.05% probability that an automotive light has two or more defective bulbs.
b. Expected number of automotive lights to check to obtain one with two or more defective bulbs.
0.0005 = 0.05% probability that an automotive light has two or more defective bulbs.
The number of expected trials to obtain n successes with p probability is given by:
[tex]E = \frac{n}{p}[/tex]
In this case, we have that [tex]n = 2, p = 0.0005[/tex]. So
[tex]E = \frac{n}{p} = \frac{2}{0.0005} = 4000[/tex]
4000 automotive lights.
Five times a number decreased by 8 is less than 37. Write an algebraic inequality to represent this situation.
Answer:
5x - 8 < 37
Step-by-step explanation:
I'm so sorry if this is wrong
For which of the following equations is (-2,-3) not a solution?
A) y=x-1
B) -3x=4y-6
C) 2y-3x=0
D) 5x+2y=-16
Answer:
B) -3x=4y-6
Step-by-step explanation:
(-2,-3); x= -2 and y= -3
B) -3x=4y-6
-3x= 4(-3) - 6= -12-6= -18
x= -18/-3=6... wrong
Total profit P is the difference between total revenue R and total cost C. Given the following total-revenue and total-cost functions, find the total profit, the maximum value of the total profit, and the value of x at which it occurs.
R(x)=1300x-x^2
C(x)=3300+20x
Will give brainliest!
Answer: Oh no... Anyway's wanna ask me a question about sex ed?
Step-by-step explanation: x=495
,P=241,525
Step-by-step explanation:
Given that
Profit=Total revenue - total cost
P= R -C
Also given that
So
Above equation is the total profit in terms if x.
Now to find maximum value of P we have to differentiate above equation with respect to x
So
⇒x=495
So total profit at x=445 ,P=241,525
Answer:
The profit function is:
[tex]P(x)=-x^2+1280x-3300[/tex]
The maximum value is 406, 300 occurring when x = 640.
Step-by-step explanation:
The revenue function is:
[tex]R(x)=1300x-x^2[/tex]
And the cost function is:
[tex]C(x)=3300+20x[/tex]
Then the total profit function will be:
[tex]P(x)=R(x)-C(x)=(1300x-x^2)-(3300+20x)=-x^2+1280x-3300[/tex]
This is a quadratic function.
Therefore, the maximum value of the total profit will occur at its vertex point.
The vertex of a quadratic is given by:
[tex]\displaystyle \Big(-\frac{b}{2a}, f\Big(-\frac{b}{2a}\Big)\Big)[/tex]
In this case, a = -1, b = 1280, and c = -3300.
Then the point at which the maximum profit occurs is at:
[tex]\displaystyle x=-\frac{1280}{2(-1)}=640[/tex]
And the maximum profit will be:
[tex]P(640)=-(640)^2+1280(640)-3300=406300[/tex]
h(t)=(49+4.9t)(10-t) solve for t
Answer:
t = ±10
Step-by-step explanation:
after using the FOIL method you have the following:
490 + 49t - 49t - 4.9t²
middle two terms zero out
h(t)= -4.9t² + 490
if you multiply by -10 you can get perfect squares
h(t) = 49t² - 4900 which has two factors: (7t + 70)(7t - 70)
now set each factor equal to zero and solve:
7t + 70 = 0
7t = -70
t = -10
7t - 70 = 0
7t = 70
t = 10
3) -2x – 3y = -7
-4x + y = 21
A) (-8, 4)
C) (2, 4)
B) (-4,5)
D) No solution
Answer: B) (-4,5)
Step-by-step explanation:
Begin the problem by solving for y with the second equation. Add -4x to both sides of the equation so it reads y=4x+21. Then, substitute y into the first equation and solve. -2x-3(4x+21)=-7 turns into -14x-63=-7, which becomes -14x=56. Divide 56/-14 to get -4 for x. Since only one answer has -4 as an option for x, that's the correct answer.
A statue of George Washington is also in Druids a 15 m away from the statue and places a mirror 12 m from the statue (3 m from her feet)she can see the top of the statue in the mirror. The girl's height is How tall is the statue(draw a diagram and solve)
Answer:

Let 'x' represent the height of the statue.
1 ft = 0.3048 m
5.5 ft = 5.5*0.3048 m
Using the similar triangles we can write:
x : 3 = 12 : (5.5*0.3048)
x = 21.47 m
The statue is 21.47 meters tall
does anyone know the answer to this.
Answer:
D
PLZ MARK AS BRAINLIEST
Step-by-step explanation:
FIRST STEP:
4*3 =12
6.5*3 =19.5
SECOND STEP:
21*12*19.5 =4914
Answer:
D
Step-by-step explanation:
i solved it
Después de aplicar un 15% de descuento, el precio de un juego de comedor es de $940. Calcular el precio inicial.
Seleccione una:
a. $1.456,80
b. $1.340,00
c. $1.000,50
d. $1.105,88
Answer:
b).$1.340,00
Step-by-step explanation:
Sana po makatulong ako sayo..
Please help me i’m sorry
Answer:
Is that 11/3 because of rise over run??? I'm not sure
at a school there are 10 students taking only chemistry, 9 students taking only physics 5 students taking both, and 16 students not taking either. if a student is randomly selected from the other school, what is the probability that they are taking chemistry or physics?
Answer:
If there are 10 students taking only chemistry, 9 students taking only physics, and 5 students only taking both chemisty and 16 students are taking neither; I would add 10+9+5+16=40 (total students) and divide 10/40 (25% chemistry) 9/40 (22.5% physics) 5/40 (12.5% both) 16/40 (40% neither)
Step-by-step explanation:
1. Determine a single event with a single outcome.
2. Identify the total number of outcomes that can occur.
3. Divide the number of events by the number of possible outcomes.
Answer:
3/5
Step-by-step explanation:
A professor of cognitive psychology is interested in the percent accuracy on this memory encoding task among college students. She measures the percent accuracy for 64 randomly selected students. The professor knows that the distribution of scores is normal, but she does not know that the true average percent accuracy on this memory encoding task among college students is 0.794 percent correct with a standard deviation of 0.1110 percent correct.
The expected value of the mean of the 64 randomly selected students, M, is ______ mean and/or standard deviation just given to calculate the expected value of M.) . (Hint: Use the population
The standard error of M is_______ (Hint: Use the population mean and/or standard deviation just given to calculate the standard error.)
Answer:
Mean of M = 0.794
Standard Error = 0.013875
Step-by-step explanation:
Given that :
Sample size, n = 64
Mean percentage accuracy, μ = 0.794
Standard deviation, σ = 0.1110
Since the distribution of scores is normal ;
Sample mean, m ~ μ
Hence, m ~ 0.794
The sample sta dard deviation of standard error ~ σ/sqrt(n)
Standard Error = 0.1110 / sqrt(64)
Standard Error = 0.1110 / 8
Standard Error = 0.013875
How do you explain how to answer this -2 - (-6)
Answer:
4
Step-by-step explanation:
so you start with the number -2 and than you add 6 because your multiplying the 2 subtraction symbols to get a positive so your answer would be 4
