Given:
p = 0.15
The mean and standard deviation(S.D) can be calculated using the formula:
![\begin{gathered} \operatorname{mean}\text{ = p} \\ S\mathrm{}D\text{ = }\sqrt[]{(p(1-p))/(n)} \end{gathered}]()
(a) A random sample of size n = 4000
mean = 0.14
SD:
![\begin{gathered} =\text{ }\sqrt[]{(0.14(1-0.14))/(4000)} \\ =\text{ }\sqrt[]{(0.1204)/(4000)} \\ \approx\text{ 0.005486} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/fondgbscukd40fr8g27jpgn8sx6k2h0bee.png)
SD = 0.005486
(b) A random sample of size n = 1000
mean = 0.14
SD:
![\begin{gathered} =\text{ }\sqrt[]{(0.14(1-0.14))/(1000)} \\ =\text{ }\sqrt[]{(0.1204)/(1000)} \\ \approx\text{ }0.01097 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/cjkoo28xfz86q3c701y125597yx72uga42.png)
SD = 0.01097
(C) A random sample of size n = 250
mean = 0.14
SD:
![\begin{gathered} =\text{ }\sqrt[]{(0.14(1-0.14))/(250)} \\ =\sqrt[]{(0.1204)/(250)} \\ \approx\text{ 0.02195} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/mtuog9i1j9oxkf9zzdgurcxccqvm5ljim7.png)
SD = 0.02195