Suppose that 25% of all males in a population are carriers of a certain infectious disease \\( (p_1= 0.25) \\) and that 28% of all females in the population are carriers \\( (p_2= 0.28). \\) Researchers who don’t know these actual numbers are interested in estimating the difference by using random samples of 100 males and 100 females to find \\( \hat p_1−\hat p_2 \! \\) .

The standard deviation of the sampling distribution of \\( \hat p_1−\hat p_2 \\) is:

A)0.062.

B)0.004.

C)0.073.

Respuesta :

Answer: A)0.062.

Step-by-step explanation:

Given : The proportion of ales in a population are carriers of a certain infectious disease : [tex]p_1= 0.25[/tex]

The proportion of all females in the population are carriers : [tex]p_2= 0.28[/tex]

Sample size of men : [tex]n_1=100[/tex]

Sample size of women : [tex]n_2=100[/tex]

The standard error of the sampling distribution of [tex]\hat{p_1}-\hat{p_2}[/tex] is given by :

[tex]\sigma_{\hat{p_1}-\hat{p_2}}=\sqrt{\dfrac{\hat{p_1}(1-\hat{p_1})}{n_1}+\dfrac{p_2(1-p_2)}{n_2}}[/tex]

Substitute all value s, we get

[tex]\sigma_{\hat{p_1}-\hat{p_2}}=\sqrt{\dfrac{0.25(1-0.25)}{100}+\dfrac{0.28(1-0.28)}{100}}[/tex]

[tex]\sigma_{\hat{p_1}-\hat{p_2}}=\sqrt{\dfrac{0.25(0.75)}{100}+\dfrac{0.28(0.72)}{100}}[/tex]

[tex]=\sqrt{0.001875+0.002016}[/tex]

[tex]=\sqrt{0.003891}=0.062377880695\apprrox0.062[/tex]

Hence, the standard deviation of the sampling distribution of [tex]\hat{p_1}-\hat{p_2}[/tex] is 0.062.

Thus , the correct answer is A)0.062.

According to the proportions given, the standard error of the sampling distribution of the differences of the proportions is given by:

A) 0.062.

For each sample, the standard errors are:

[tex]s_1 = \sqrt{\frac{0.25(0.75)}{100}} = 0.0433[/tex]

[tex]s_2 = \sqrt{\frac{0.28(0.72)}{100}} = 0.0449[/tex]

For the distribution of differences, it is the square root of the sum of the standard errors of each sample squared, hence:

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

[tex]s = \sqrt{0.0433^2 + 0.0449^2}[/tex]

[tex]s = 0.062[/tex]

Option A.

A similar problem is given at https://brainly.com/question/16695444