An industrial sales manager, testing the effectiveness of three different sales presentations ...

An industrial sales manager, testing the effectiveness of three different sales presentations, randomly selected a presentation to be used when making the next sales call on 14 customers. The numbers of units purchased as a result of each sales call are shown below. Use the .05 level in determining whether the three sales presentations could be equally effective.

Presentation 1

7,9,11,7

Presentation 2

13,10,11,13,14

Presentation 3

14,15,12,10,13