Construct a Confidence Interval For $\mu _ { \mathrm { d } }$

Construct a confidence interval for $\mu _ { \mathrm { d } }$ , the mean of the differences d for the population of paired data. Assume that the
population of paired differences is normally distributed.
-When 25 randomly selected customers enter any one of several waiting lines, their waiting times have a
standard deviation of 5.35 minutes. When 16 randomly selected customers enter a single main waiting line,
their waiting times have a standard deviation of 2.2 minutes. Use a 0.05 significance level to test the claim that
there is more variation in the waiting times when several lines are used.