4.The World Health Organization reports thatin a sample of 10,013 people globally, 9 in 31 people do not have access to drinking water free from contamination.

a) Find a 95% confidence interval for the population proportion of people globally who do not have access to drinking water free from contamination.

b) Find a 99% confidence interval for the population proportion of people globally who do not have access to drinking water free from contamination.

c)The number of people used in the sample for part a was 10,013.Which of the following sample sizes would also satisfy normality: 15, 20, 30, 75, 200 when using a 95% level of confidence?You must show work for this problem.Explain your reasoning.