The IRS randomly selected 2950 tax returns for audit and discovered that 1900 of them had serious errors. The sample is larger so that sample classical confidence interval for p may be used below.
a) What was the sample proportion of tax returns that had erious errors?
b) What is the z(? / 2) critical value that would be used to create a 98% confidence interval for the true proportion of tax returns with serious errors?
c) Construct a large sample 98% classical confidence interval for the true proportion of tax returns with serious errors.
d) What is the smallest sample size that would guarantee that the 98% confidence interval for the true proportion of tax with serious errors would have length .01 or less?