Statistics Help please

Question

You are interested in estimating the the mean age of the citizens living in your community. In order to do this, you plan on constructing a confidence interval; however, you are not sure how many citizens should be included in the sample. If you want your sample estimate to be within 5 years of the actual mean with a confidence level of 98%, how many citizens should be included in your sample? Assume that the standard deviation of the ages of all the citizens in this community is 17 years. (Use Excel to find the appropriate critical value and round it to 3 decimal places.)

Sample Size: 

Answer 1

margin of error (E) = z-critical*s/n**0.5

n**0.5 = (z-critical*s/E)

n = (z-critical*s/E)**2

E = 5, z-critical = 2.33, s = 17

n = (2.33*17/5)**2= 62.75 ~ 63