A confidence interval for the difference between the means of two normally distributed populations based on the

Question:

A confidence interval for the difference between the means of two normally distributed populations based on the following dependent samples is desired:
Before After
6 ............ 8
12 ................14
8 ............ 9
10 ................13
6 ................. 7
a. Find the margin of error for a 90% confidence level.
b. Find the UCL and the LCL for a 90% confidence level.
c. Find the width of a 95% confidence interval.