In a study of 443 nonprofits nationwide, 130 indicated that the greatest diversity staffing challenge they face is retaining younger staff (those under 30).

Source: Data extracted from “2016 Nonprofit Employment Practices Survey,” Nonprofit HR, 2016, bit.ly/23ZHwhb.

a. Construct a 95% confidence interval for the population proportion of nonprofits that indicate retaining younger staff is the greatest diversity staffing challenge for 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 retaining younger staff is the greatest diversity staffing challenge for their organization to within ±0.01 with 95% confidence, how many nonprofits would you survey?