The average purchase size from your online sales site is $17, 200. The customer experience team believes a
certain adjustment of the website will increase sales. A pilot study on a few hundred customers showedan
increase in average purchase size of $1.47, with a significance level of p=0.1. The team runs a largerstudy, of
a few thousand customers. The second study shows anincreased average purchase size of $0.74, with a
significance level of 0.03. What is your assessmentof this study?

A.
The change in purchase size is not practically important,and the good p-value of the second study is
probably a result of the large study size.

B.
The change in purchase size is small,but may aggregate up to a large increase in profits over the entire
customer base.

C.
The difference in the change in purchase size between the two studies is troubling; The team should run
another,larger study.

D.
The p-value of the second study shows a statistically significant change in purchase size. The new website
is an improvement.