In a study of 413 nonprofits nationwide, 83 indicated that turnover has been the biggest employment challenge at their organization. (Source: Nonprofit HR, 2014 Nonprofit Employment Practices Survey, available at bit.ly/1mfy2tJ.)

a. Construct a 95% confidence interval for the population proportion of nonprofits that indicate turnover as the biggest employment challenge at their organization.

b. Interpret the interval constructed in (a).

c. If you wanted to conduct a follow- up study to estimate the population proportion of nonprofits that indicate turnover as the biggest employment challenge at their organization to within ± 0.01 with 95% confidence, how many nonprofits would you survey?