What is the value of the expression?<br> 84-24428<br> 13<br> 115<br> 13.4<br> 152<br> O

pychu [463]

I think 42

would be the best answer to your question in my opininon.

7 0

3 years ago

Many elementary school students in a school district currently have ear infections. A random sample of children in two different

Marta_Voda [28]

Answer:

Step-by-step explanation:

The summary of the given data includes;

sample size for the first school $n_1$ = 42

sample size for the second school $n_2$ = 34

so 16 out of 42 i.e $x_1$ = 16 and 18 out of 34 i.e $x_2$ = 18 have ear infection.

the proportion of students with ear infection Is as follows:

$\hat p_1 = \dfrac{16}{42}$ = 0.38095

$\hat p_2 = \dfrac{18}{34}$ = 0.5294

Since this is a two tailed test , the null and the alternative hypothesis can be computed as :

$H_0 :p_1 -p_2 = 0 \\ \\ H_1 : p_1 - p_2 \neq 0$

level of significance ∝ = 0.05,

Using the table of standard normal distribution, the value of z that corresponds to the two-tailed probability 0.05 is 1.96. Thus, we will reject the null hypothesis if the value of the test statistics is less than -1.96 or more than 1.96.

The test statistics for the difference in proportion can be achieved by using a pooled sample proportion.

$\bar p = \dfrac{x_1 +x_2}{n_1 +n_2}$

$\bar p = \dfrac{16 +18}{42 +34}$

$\bar p = \dfrac{34}{76}$

$\bar p = 0.447368$

$\bar p + \bar q = 1 \\ \\ \bar q = 1 -\bar p \\ \\\bar q = 1 - 0.447368 \\ \\\bar q = 0.552632$

The pooled standard error can be computed by using the formula:

$S.E = \sqrt{ \dfrac{ \bar p \bar q}{ n_1} + \dfrac{\bar p \bar p}{n_2} }$

$S.E = \sqrt{ \dfrac{ 0.447368 * 0.552632}{ 42} + \dfrac{ 0.447368 * 0.447368}{34} }$

$S.E = \sqrt{ \dfrac{ 0.2472298726}{ 42} + \dfrac{ 0.2001381274}{34} }$

$S.E = \sqrt{ 0.01177284105}$

$S.E = 0.1085$

The test statistics is ;

$z = \dfrac{\hat p_1 - \hat p_2}{S.E}$

$z = \dfrac{0.38095- 0.5294}{0.1085}$

$z = \dfrac{-0.14845}{0.1085}$

z = - 1.368

Decision Rule: Since the test statistics is greater than the rejection region - 1.96 , we fail to reject the null hypothesis.

Conclusion: There is insufficient evidence to support the claim that a difference exists between the proportions of students who have ear infections at the two schools

5 0

3 years ago

Can anyone help it would mean alot im struggling right now

Setler79 [48]

Answer:

what do you need? ^-^ I can help you

6 0

2 years ago

I WILL AWARD BRAINLIEST!! PLEASE HELP!!! The figure below shows the movement of a pedestrian from point B to point E. Using the

jeyben [28]

Answer:

Step-by-step explanation:

A) What is the speed of the pedestrian BC, CD, and DE?

Speed from B to C = distance/time = (40 - 20) / 4 = 20/4

= 5 km/h

Speed from C to D = distance/time = 0 / 2

= 0 km/h

Speed from D to E = distance/time = (20 - 0) / (10 - 6) = 20/4

= 5 km/h

B) After what time since the stop did he arrive at point E?

Since the stop at D, he arrived at E after (10 - 6) = 4 h

C) Write the formulas for function d(t) for sections BC, CD, and DE

For BC, d = 40 when t = 0 and d = 20 when t = 4

So d(t) = 40 - 5t

For CD, d = 20 when t = 4 and t = 6

So d(t) = 20

For DE, d = 20 when t = 6 and d = 0 when t = 10

So d(t) = 5 * (10 - t) or d(t) = 50 - 5t

4 0

3 years ago

Read 2 more answers

∠ R and∠ S are complementary. If m ∠ R = 12x - 3 and m ∠ S = 7x - 2, find m ∠ R.

Paha777 [63]

Step-by-step explanation:

<h2>Sum of two complementary angle is 90°</h2><h2 /><h2>so. </h2><h2><R+<S =90°</h2><h2>12x-3+7x-2=90°</h2><h2>19x-5=90°</h2><h2>19x=95°</h2><h2>X= 5</h2>

3 0

3 years ago

What is the value of the expression? 84-24428 13 115 13.4 152 O