Help me please I need help

Answer:

The 90% confidence interval for the difference in the mean grade on test 7 for all students who attended a review session and for all students who did not attend a review session is (3.7, 12.3).

Step-by-step explanation:

Before building the confidence interval, we need to understand the central limit theorem and subtraction between normal variables.

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.

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Subtraction between normal variables:

When two normal variables are subtracted, the mean is the difference of the means, while the standard deviation is the square root of the sum of the variances.

A simple random sample of 22 students who attended a review session was selected, and the mean grade on test 7 for this sample of 22 students was 85 with a standard deviation of 9.8.

This means that:

[tex]\mu_A = 85, s_A = \frac{9.8}{\sqrt{22}} = 2.09[/tex]

An independent simple random sample of 47 students who did not attend a review session was selected, and the mean grade on test 7 was 77 with a standard deviation of 10.6.

This means that:

[tex]\mu_N = 77, s_N = \frac{10.6}{\sqrt{47}} = 1.55[/tex]

Distribution of the difference in the mean grade on test 7 for all students who attended a review session and for all students who did not attend a review session.

Mean:

[tex]\mu = \mu_A - \mu_N = 85 - 77 = 8[/tex]

Standard deviation:

[tex]s = \sqrt{s_A^2 + s_B^2} = \sqrt{2.09^2 + 1.55^2} = 2.6[/tex]

Confidence interval:

We have that to find our [tex]\alpha[/tex] level, that is the subtraction of 1 by the confidence interval divided by 2. So:

[tex]\alpha = \frac{1 - 0.9}{2} = 0.05[/tex]

Now, we have to find z in the Ztable as such z has a pvalue of [tex]1 - \alpha[/tex].

That is z with a pvalue of [tex]1 - 0.05 = 0.95[/tex], so Z = 1.645.

Now, find the margin of error M as such

[tex]M = zs[/tex]

So

[tex]M = 1.645*2.6 = 4.3[/tex]

The lower end of the interval is the sample mean subtracted by M. So it is 8 - 4.3 = 3.7

The upper end of the interval is the sample mean added to M. So it is 8 + 4.3 = 12.3

The 90% confidence interval for the difference in the mean grade on test 7 for all students who attended a review session and for all students who did not attend a review session is (3.7, 12.3).

Answer:

I think you can answer it with a chart, I guess, of course I'm not sure‍♀️

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Answer: -0.833 (repeating decimal)

Step-by-step explanation: fg(x) means plug the g(x) equation into f(x), and for gf(x) it’s vice versa:

Fg(x) = 3x^2 - 1 + 2

Gf(x) = 3(x + 2)^2 - 1

First, we should simplify gf(x) to eliminate the (x + 2)^2:

3(x^2 + 4x + 4) - 1

3x^2 + 12x + 12 - 1

3x^2 + 12x + 11

Second, simplify fg(x) by solving -1 + 2: 1

Now, we can set the two equations equal to each other and solve:

3x^2 + 1 = 3x^2 + 12x + 11 (subtract 3x^2 from each other and 1 from 11)

-10 = 12x (Divide)

-0.8333... = x

To make sure this answer is correct, plug -0.833 into the original equations and set them equal to each other:

3(-0.833)^2 + 1 = 3(-0.833)^2 + 12(-0.833] + 11

3.083 = 3.083

Answer:

17 ft

Step-by-step explanation:

The triangle on the bottom left is a right triangle.

a² + b² = c²

(8 ft)² + (15 ft)² = (RQ)²

64 ft² + 225 ft² = (RQ)²

(RQ)² = 289 ft²

RQ = 17 ft

Answer:

Solution given.

f = 5, g = 6, h = 7

<F=?

we have;

f² = g² + h² – 2gh cos F

5²-6²-7²=-2×6×7 cos F

-60/-84=cos F

F=cos-¹(5/7)=44.41°

<F=44.4° is a required answer

Answer:

60,000

Step-by-step explanation:

Answer:

60,000

Step-by-step explanation:

Answer: 3 7/20

Step-by-step explanation:

5 3/5 - 2 1/4

Find GCD.

5 12/20 - 2 5/20

3 7/20 more boxes of raspberries than strawberries

Answer: 292

Step-by-step explanation:

Given

There are 240 members in a labor union

The number increases by 5% each year

After 1 year it is

[tex]\Rightarrow 240+5\%\times 240\\\Rightarrow 240(1+0.05)[/tex]

After 2 years

[tex]\Rightarrow 240(1+0.05)+5\%\times 240(1+0.05)\\\Rightarrow 240(1+0.05)(1+0.05)=240(1+0.05)^2[/tex]

Similarly, after 4 years

[tex]\Rightarrow 240(1+0.05)^4\\\Rightarrow 291.72\approx 292[/tex]

Answer:

Your answer should be 155!

Step-by-step explanation:

Sum means to add, so 24 + 7 = 31

31 x 5 = 155

I hope this helps!

A summation, also called a sum, is the result of arithmetically adding numbers or quantities. 155 is the answer for 5 times the sum of 24 and 7.

A summation, also called a sum, is the result of arithmetically adding numbers or quantities.

Given,

5 times the sum of 24 and 7

Sum is nothing but addition.

When we see the word sum it means we are adding some value with other factor. In the given problem 24 and 7 are added.

Times means multiplication.

We have to convert 5 times the sum of 24 and 7 to expression.

When we see times, it means product or we are multiplying a number with the other number. Here with 5 we are multiplying the sum of 24 and 7.

5×(24+7)

Firstly we calculate value in parenthesis.

twenty four plus seven is thirty one.

5×31

The product of 5 and 31 is 155.

155

Hence 155 is the answer for 5 times the sum of 24 and 7.

To learn more on Sum click:

https://brainly.com/question/13013054

#SPJ2

Answer:

friend alone could do it in 13 hours and 1/3

Step-by-step explanation:

Your rate = room/8

friends rate = room/x

combined rate = room/8 + room/x

= room(x+8)/(8x)

then

5 = room / [room(x+8)/(8x)]

5 = 8x/(x+8)

8x = 5x + 40

3x = 40

x = 40/3 = 13 1/3

friend alone could do it in 13 hours and 1/3

Answer:

90,000

Step-by-step explanation:

As an estimate

200 * 450

which is 90,000

Answer:

a4 = 189

Step-by-step explanation:

Geometric sequence:

In a geometric sequence, the quotient r between consecutive terms is always the same.

The nth term of the sequence is given by:

[tex]a_n = a_1*r^{n-1}[/tex]

In which [tex]a_1[/tex] is the first term.

In this question:

[tex]a_1 = 7, r = 3[/tex]

The fourth term is:

[tex]a_4 = 7*3^3 = 189[/tex]

So

a4 = 189

Answer:

Can you give it in a english

Step-by-step explanation:

Answer:

2option is the correct answer

Answer:

[tex] \frac{8}{1} [/tex]

Step-by-step explanation:

[tex] \frac{ - 32}{ - 4} [/tex]

Reduce factor by 4

[tex] \frac{ - 8}{ - 1} [/tex]

A negative divided by a negative equal positve so

[tex] \frac{8}{1} [/tex]

the simplest form of 32/4 is 8/1

find the GCD ( or HCF) of numerator and denominator GCD of 32 4 is 4

divide both the numerator and denominator GCD

32/4 ÷ 4/4

reduce fraction: 8/1

therefore, 32/4 simplify to lowest terms is 8/1.

Answer:

C: The median

Step-by-step explanation:

1. Use sharpie to cover up private information before throwing it away (because people can look through your trash for your info). For example: credit card information, your address, etc.

2. Secure your mail box. Get a lock to make sure that people won't steal your credit card information.

3. Never ever leave your receipts behind.

4. Don't lose your credit card!! People can steal it can spend your money!

5. Just don't give random people or friends your credit card information...

Well, I hope this helped! Be careful and stay safe!

Answer:

Step-by-step explanation:

Answer:

the bottom left

Step-by-step explanation:

A linear function will have a constant slope so the bottom left graph is the only one with a constant slope. The y-values are all increasing by 2.

Answer:

-6,-2 is the answer!!

Step-by-step explanation:

The coordinate of A' would be (-6, -2)

Dilation is a transformation technique that changes the size of an object by a scale factor "k"

From the diagram shown, the measure of the coordinate point is given as (-3, -1).

If the coordinate A is dilated by a factor of 2, the resulting coordinate A' will be given as:

A' = (2(-3), 2(-1)) = (-6, -2)

Hence the  coordinate of A' would be (-6, -2)

Learn more on dilation here: https://brainly.com/question/3457976

Calculate the missing values.

Jill Kingman pays a $419.00 premium annually. This represents 35% of the total premium. The rest of the premium is paid by her employer.

Use a thousands comma where applicable.

1. 100 (100% of cost)  - 35 = 65% company percent

2. 419.00 ÷ .35 (or, 35%, but use the decimal) = 1197 total premium

3. 0.65 × 1197 = 778.05 company payment

I tried to make it so you could see where the numbers came from, by making the ones bold, others, italics, and other combinations. I hope you understand what I did. I tried to explain how the guy above did it. He did well, so brainliest goes to him.

Answer:

4+3+6+2 = 15

Step-by-step explanation:

selecting a yellow marker 4/15

selecting a red marker 2/15

Answer:

In order of pictures,

Picture #1: 230

Picture #2: 140

Picture #3: 9.9

Picture #4: 13.5

Picture #5: 7.07

Step-by-step explanation:

I am not entirely sure that 3 - 5 are correct, but I know that 1 and 2 are correct. I am sorry if they are incorrect.

Hope that this helps!

Answer:

1/6 = 1/6 (already simplified) 1 3/8 = 11/8

Step-by-step explanation:

Step-by-step explanation:

the circle to any point on the circle

Answer:

Radius

.....................

Answer:

Quadrant I and Quadrant II

Step-by-step explanation:

Quadrant I has both positive x and y coordinates,Quadrant II has a negative x coordinate but the y coordinate is positive.

Answer:

5.5

Step-by-step explanation:

5 + 6 =

11 / 2 =

5.5

Answer:

it's (6,0) I can't explain though