A company is researching the effectiveness of a new website design to decrease the time to access a website. Five website users were randomly selected, and their times (in seconds) to access the website with the old and new designs were recorded. To compare the times, they computed (new website design time - old website design time). The results follow.

user Old webdesign New web design A 30 25 B45 30 C 25 20

D 32 30

E28 27

for a .01 significance level, what is the critical value?