A professor has a teaching assistant record the amount of time (in minutes) that a sample of 16 students engaged in an active discussion. The assistant observed 8 students in a class who used a slide show presentation and 8 students in a class who did not use a slide show presentation.

With Microsoft PPT Without Microsoft PPT

13 15

12 19

21 23

8 11

9 10

7 18

6 4

5 14

Use the normal approximation for the Mann-WhitneyUtest to analyze the data above. (Round your answer to two decimal places.)

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