ACTIVITY

Suppose the police commissioner in a small town must chose between two plans for patrolling the twon's streets. Plan A, the less expensive plan, uses voluntary citizen groups to patrol certain high-risk neighborhoods. In contrast, plan B would utilize police patrols. Both plans are examined by 10 trained criminologists, each of whom is asked to rate the plans on a scale from 1 to 10. (High ratings imply a more effective crime prevention plan.) The city will adopt plan B (and hire extra police) only if the data provide sufficient evidence that criminologists tend to rate plan B more effective than plan A.

The results of the survey are shown below:

By using the following steps and the Statlets window provided at the end of this page test the hypothesis that plan B ratings exceed those of plan A.

• Step 1: Make sure that "Input" menu option is selected.
• Step 2: Double click on "Col_1" and replace it with "Plan A".
• Step 3: Enter the data for the plan A.
• Step 4: Double click on "Col_2" and replace it with "Plan B".
• Step 5: Enter the data for the plan B.
• Step 6: Click on the right arrow at the upper right corner until you see "Rank test".
• Step 7: Select the "Rank test " from menu options. Do not use the output yet.
• Step 8: Click on the "Options" button and select "Less than" for Alternative hypothesis.
• Step 9: Click "OK".

Interpret the output and state your conclusion.