The below sample data represents the cost of 9 name-brand drugs and their corresponding generic equivalent. (Use Name Brand as Sample1)
Name
Brand 120 150 135 140 160 175 140 120 165
Generic
Brand 99 135 130 119 139 150 129 109 160
a) Compute a two-sided 90% confidence Interval estimate for µd.
b) Based on your interval, can you safely conclude that generics are less expensive than name brand? Why or why not?