A Political Advisor Believes That His Candidate Should Not Spend

Not Answered

A political advisor believes that his candidate should not spend time addressing groups of voters who have a low opinion of him. The advisor reasons if they have a low opinion the voter won t change his mind anyway. To test this idea the advisor gets a group from an audience to rate the candidate before and after a speech. From this group he selects a sample of voters who initially rated the candidate poorly and then analyzes the effect of the speech. Here are the data. A higher rating indicates a higher opinion.
a. What is the value of T obt ?
b. What do you conclude using a = 0.05 1 tail ?
c. What type error might one be making?