Answer:
Step-by-step explanation:
The summary of the given data includes;
sample size for the first school
= 42
sample size for the second school
= 34
so 16 out of 42 i.e
= 16 and 18 out of 34 i.e
= 18 have ear infection.
the proportion of students with ear infection Is as follows:
= 0.38095
= 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](https://tex.z-dn.net/?f=H_0%20%3Ap_1%20-p_2%20%3D%200%20%5C%5C%20%5C%5C%20H_1%20%3A%20p_1%20-%20p_2%20%5Cneq%200)
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}](https://tex.z-dn.net/?f=%5Cbar%20p%20%3D%20%5Cdfrac%7Bx_1%20%2Bx_2%7D%7Bn_1%20%2Bn_2%7D)
![\bar p = \dfrac{16 +18}{42 +34}](https://tex.z-dn.net/?f=%5Cbar%20p%20%3D%20%5Cdfrac%7B16%20%2B18%7D%7B42%20%2B34%7D)
![\bar p = \dfrac{34}{76}](https://tex.z-dn.net/?f=%5Cbar%20p%20%3D%20%5Cdfrac%7B34%7D%7B76%7D)
![\bar p = 0.447368](https://tex.z-dn.net/?f=%5Cbar%20p%20%3D%200.447368)
![\bar p + \bar q = 1 \\ \\ \bar q = 1 -\bar p \\ \\\bar q = 1 - 0.447368 \\ \\\bar q = 0.552632](https://tex.z-dn.net/?f=%5Cbar%20p%20%2B%20%5Cbar%20%20q%20%3D%201%20%5C%5C%20%5C%5C%20%5Cbar%20q%20%3D%201%20-%5Cbar%20%20p%20%5C%5C%20%20%5C%5C%5Cbar%20q%20%3D%201%20-%200.447368%20%5C%5C%20%5C%5C%5Cbar%20q%20%3D%200.552632)
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} }](https://tex.z-dn.net/?f=S.E%20%3D%20%5Csqrt%7B%20%5Cdfrac%7B%20%5Cbar%20p%20%5Cbar%20q%7D%7B%20n_1%7D%20%2B%20%20%5Cdfrac%7B%5Cbar%20p%20%5Cbar%20p%7D%7Bn_2%7D%20%7D)
![S.E = \sqrt{ \dfrac{ 0.447368 * 0.552632}{ 42} + \dfrac{ 0.447368 * 0.447368}{34} }](https://tex.z-dn.net/?f=S.E%20%3D%20%5Csqrt%7B%20%5Cdfrac%7B%20%200.447368%20%2A%20%200.552632%7D%7B%2042%7D%20%2B%20%20%5Cdfrac%7B%200.447368%20%2A%20%200.447368%7D%7B34%7D%20%7D)
![S.E = \sqrt{ \dfrac{ 0.2472298726}{ 42} + \dfrac{ 0.2001381274}{34} }](https://tex.z-dn.net/?f=S.E%20%3D%20%5Csqrt%7B%20%5Cdfrac%7B%20%200.2472298726%7D%7B%2042%7D%20%2B%20%20%5Cdfrac%7B%200.2001381274%7D%7B34%7D%20%7D)
![S.E = \sqrt{ 0.01177284105}](https://tex.z-dn.net/?f=S.E%20%3D%20%5Csqrt%7B%200.01177284105%7D)
![S.E = 0.1085](https://tex.z-dn.net/?f=S.E%20%3D%200.1085)
The test statistics is ;
![z = \dfrac{\hat p_1 - \hat p_2}{S.E}](https://tex.z-dn.net/?f=z%20%3D%20%5Cdfrac%7B%5Chat%20p_1%20-%20%5Chat%20p_2%7D%7BS.E%7D)
![z = \dfrac{0.38095- 0.5294}{0.1085}](https://tex.z-dn.net/?f=z%20%3D%20%5Cdfrac%7B0.38095-%200.5294%7D%7B0.1085%7D)
![z = \dfrac{-0.14845}{0.1085}](https://tex.z-dn.net/?f=z%20%3D%20%5Cdfrac%7B-0.14845%7D%7B0.1085%7D)
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