1.Suppose that in a random sample of 250 voters, 142 plan to vote for a particular candidate.For each question below, write your answer as a decimal, rounding to three places as necessary.

(a) Find a point estimate for p, the population proportion of all voters who plan to vote for the candidate.

(b)Construct a 90% confidence interval for the population proportion of voters who plan to vote for the candidate.

(c) What sample size is needed so that a 95% confidence interval has a margin of error of 0.04?Use the preliminary estimate given in this problem.

(d)What sample size is needed so that a 95% confidence interval has a margin of error of 0.04?Assume no preliminary estimate was available.