Please Answer Correctly and you must use Excel and show your workings.

2. A random sample of the amounts for 24 purchases was taken. The mean was $49.86, the standard deviation was $20.41, and the margin of error for a 95% confidence interval was $8.62. Assume that t*-,=2.0 for the 95% confidence intervals. a) To reduce the margin of error to about $4, how large would the sample size have to be? b) How large would the sample size have to be to reduce the margin of error to 0.8