Question

A learn-to-type software program claims that it can improve your typing skills. To test the claim and possibly help yourself out, you and three of your friends decide to try the program and see what happens. Use the table below to construct an 80% confidence interval for the true mean change in the typing speeds for people who have completed the typing program. Round your answer to one decimal place.

Typing Speeds (in Words per Minutes) Before After 42 54 50 52 37 41 22 30

lower endpoint =

upper endpoint =

Answer 1