For a population data set, = 14.50. a. What should the sample size be for a

Question:

For a population data set, σ = 14.50.
a. What should the sample size be for a 98% confidence interval for µ to have a margin of error of estimate equal to 5.50?
b. What should the sample size be for a 95% confidence interval for µ to have a margin of error of estimate equal to 4.25?