Lower and Upper endpoint

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 eight of your friends decide to try the program and see what happens. Use the table below to construct a 90 % confidence interval for the true mean change in the typing speeds for people who have completed the typing program. Let Population 1 be the typing speed before taking the program and Population 2 be the typing speed after taking the program. Round the endpoints of the interval to one decimal place, if necessary. Typing Speeds (in Words per Minute) Before After 43 36 42 32 48 32 48 48 46 30 32 33 I 44 43 54 31 E 37 43 Tables Keypad