Two researchers conducted a study in which two groups of students were asked to answer 42 trivia questions from a board game. The students in group 1 were asked to spend 5 minutes thinking about what it would mean to be aprofessor, while the students in group 2 were asked to think about soccer hooligans. These pretest thoughts are a form of priming. The 200 students in group 1 had a mean score of 24.4 with a standard deviation of 4.8, while the 200 students in group 2 had a mean score of 18.4 with a standard deviation of 2.9. Complete parts (a) and (b) below.

(a) Determine the 95% confidence interval for the difference inscores, 12. Interpret the interval.

The lower bound is

nothing

.

The upper bound is

nothing

.

(Round to three decimal places asneeded.)