Need help pls help will gift extra points if help plz explain how you soved it

Answer:

The test statistic is [tex]z = -0.28[/tex]

Step-by-step explanation:

First, before finding the test statistic, we need to understand the central limit theorem and difference 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 random sample of children in two different schools found that 16 of 40 at one school

This means that:

[tex]p_1 = \frac{16}{40} = 0.4, s_1 = \sqrt{\frac{0.4*0.6}{40}} = 0.0775[/tex]

13 of 30 at the other had this infection.

This means that:

[tex]p_2 = \frac{13}{30} = 0.4333, s_2 = \sqrt{\frac{0.4333*0.5667}{30}} = 0.0905[/tex]

Conduct a test to answer if there is sufficient evidence to conclude that a difference exists between the proportion of students who have ear infections at one school and the other.

At the null hypothesis, we test if there is no difference, that is:

[tex]H_0: p_1 - p_2 = 0[/tex]

And at the alternate hypothesis, we test if there is difference, that is:

[tex]H_a: p_1 - p_2 \neq 0[/tex]

The test statistic is:

[tex]z = \frac{X - \mu}{s}[/tex]

In which X is the sample mean, [tex]\mu[/tex] is the value tested at the null hypothesis and s is the standard error

0 is tested at the null hypothesis:

This means that [tex]\mu = 0[/tex]

From the two samples:

[tex]p = p_1 - p_2 = 0.4 - 0.4333 = -0.0333[/tex]

[tex]s = \sqrt{s_1^2+s_2^2} = \sqrt{0.0775^2+0.0905^2} = 0.1191[/tex]

Value of the test statistic:

[tex]z = \frac{X - \mu}{s}[/tex]

[tex]z = \frac{-0.0333 - 0}{0.1191}[/tex]

[tex]z = -0.28[/tex]

The test statistic is [tex]z = -0.28[/tex]

Answer:

Question 1: The amount of students that Yolanda kept track of doesn't add up to her sample space.

Question 2: The sample space is 237. I know this because it said in the question she was asking all of the students at their Middle School which happened to be 237. A sample space is the group that you are taking information from. They are taking information from 237 students.

Answer:

answer: m = 125

Step-by-step explanation:

parellograms add up to a total of 360 so m = 125 because 125 + 125 + 55 + 55 = 360 Hope this helps!

Step-by-step explanation:

here's your solution

==> sum of corresponding angles of parallelogram = 180°

==> angle J + angle k = 180°

==> 55° + k = 180°

==> k = 180° - 55°

==> k = 125°

[tex]hope \: it \: helps[/tex]

Answer:

192 miles

Step-by-step explanation:

This is a right triangle problem

One leg of the triangle is

50 * 3 = 150

The other leg is

40 * 3 = 120

the distance is the hypotenuse

c^2 = 150^2 + 120^2

c^2 = 22500 + 14400

c^2 = 36900

Take the square root of both sides

c = 192.093727123

c ≈ 192 miles

Answer:

30 miles apart

Step-by-step explanation:

Im not sure if this is the corect answer to this but this is what i think what i did was get 50 x 3 and 40 x 3 since they starded at the same times and finished after 3 hours so multiply your numbers by 3 so...

50 x 3=150

40 x 3=120

150-120=30 miles apart

Answer:

200+400=600

400/600=2/3=66.6%

Answer:

30%

Also I LOVE THE EMMA PIC!!!!!!!!

Answer:

its A

Step-by-step explanation:

its A ️ ‍♀️ ️ ‍♂️ ️

Answer:

The monthly payments of said financing plan will be $8.33.

Step-by-step explanation:

To determine what is the total of 12 monthly payments of $ 100.00 including tax, the following calculation must be performed:

100/12 = X

8.33 = X

Therefore, the monthly payments of said financing plan will be $8.33.

Answer:

180=3x+7x+10

simplify

180=10x+10

subtract 10 from both sides

170=10x

divide both sides by 10

x=17

Answer:

30 m

Step-by-step explanation:

You simply add the lengths of all the sides. 3 m is not needed for this.

Answer:

10+5+4+6+5 = 30m

Step-by-step explanation:

Answer:

[tex]x = \frac{5}{2}[/tex]

Step-by-step explanation:

y = 130 - 4x

======================

120 = 130 - 4x

-10 = -4x

x = [tex]\frac{-10}{-4} =\frac{5}{2}[/tex]

9. Multiply the money he has by the portion he spent:

75 x 3/5 = (75 x3)/5 = 225/5 = 45

He spent $45

10. First rewrite 4 1/8 as an improper fraction

33/8

Now multiply by 1/3:

33/8 x 1/3 = (33 x1) /(8 x 3) = 33/24 = 1 3/8

She spent 1 3/8 hours studying math.

Answer:

The margin of error is of 0.3012, and it means that we should be 99% confident that the population mean would be within 0.3012 of the sample mean.

Step-by-step explanation:

Margin of error

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

In which [tex]\sigma[/tex] is the standard deviation and n is the size of the sample.

Standard deviation of 1.3

This means that [tex]\sigma = 1.3[/tex]

She surveys 124 families

This means that [tex]n = 124[/tex]

Margin of error and meaning:

[tex]M = z\frac{\sigma}{\sqrt{n}}[/tex]

[tex]M = 2.58\frac{1.3}{\sqrt{124}}[/tex]

[tex]M = 0.3012[/tex]

The margin of error is of 0.3012, and it means that we should be 99% confident that the population mean would be within 0.3012 of the sample mean.

Answer:

The answer is C.

Step-by-step explanation:

angle 5 and 4 makes a line which is 180 and since angle 5 equals 57 , 180-57=123.

Answer:

this may help you.look it once

Step-by-step explanation:

.

Answer:

by SSS axiom

hope it helps.

Answer:

Step-by-step explanation:

Yes

the two sides that are marked make 2/3 of the sides needed for SSS

The line shared by both triangles make the third side.

Answer: SSS

Answer:

1+1 is cannot be

Step-by-step explanation:

jajauajhwhahwwhhahwhauwu

Answer:

the surface area is 48in^2 because there are 4 faces and you have to find the surface are in which you must multiply 12 by 4.

Step-by-step explanation:

Answer:

D

Step-by-step explanation:

Answer:

x = -2

x = -1

x = 0

Step-by-step explanation:

Find three numbers to the left of -3 on the number line

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

180degreesStep-by-step explanation:

Given the complex value

z² = -81i

z = (-81i)^1/2

Get the argument of -81i

theta = arctan(y/x)

theta = arctan(-81/0)

theta = -90degrees

theta = -π/2

Since tan is negative in the secind quadrant

theta =  π - π/2

theta = π/2

According to demoivres theorem

theta = 1/2 * π/2

theta = π

theta = 180degrees

Answer:

[tex]117 = 66 + \beta \\ \beta = 51[/tex]

Answer:

answer: 85

Step-by-step explanation:

These add up to 360 and

85 + 85 + 95 + 95 = 360 so 85 is the answer.

Hope that helps!

Answer:

27 cents

Step-by-step explanation:

10% of 90= 9

9x3=27

Answer:

p x t x r / 100

90 x 10 x 3 / 100

=27

Answer:

x = 35

y = 95

Step-by-step explanation:

(For y) The measure of a line is 180 degress. 180 - 95 - 50 = 35.

(For x) The measure of a triangle is 180 degress. 180 - 50 - 35 = 95.

Answer:

x = 85, y = 45

Step-by-step explanation:

solving for x:

180 - 95 = 85

solving for y:

85 + 50 = 135

180 - 135 = 45

Good luck on your schoolwork