In a classic study (Green and Rao, 1972), 21 Wharton School MBA students and their spouses were asked to rate different breakfast foods on a scale from 1 (most preferred) to 15 (least preferred).This section includes short-answer and calculation questions related to this data. The point value for each question is noted.

The following table shows the preference rating for jelly donuts for each of 21 males in the survey. Given this data, answer the following questions.

3	1	2
14	3	10
14	5	11
6	10	14
4	13	11
15	5	5
4	14	14

1. Calculate the range

2. What is the level of measurement for this variable?

3. Calculate the mean preference rating for jelly donuts.