image2.37 Body mass and metabolic rate. Metabolic rate, the rate at which the body consumes energy, is important in studies of weight gain, dieting, and exercise. The following table gives data on the lean body mass and resting metabolic rate for 12 women and 7 men who are subjects in a study of dieting. Lean body mass, given in kilograms, is a person’s weight leaving out all fat. Metabolic rate is measured in calories burned per 24 hours, the same calories used to describe the energy content of foods. The researchers believe that lean body mass is an important influence on metabolic rate.

Subject Sex Mass Rate Subject Sex Mass Rate
1 M 62.0 1792 11 F 40.3 1189
2 M 62.9 1666 12 F 33.1 913
3 F 36.1 995 13 M 51.9 1460
4 F 54.6 1425 14 F 42.4 1124
5 F 48.5 1396 15 F 34.5 1052
6 F 42.0 1418 16 F 51.1 1347
7 M 47.4 1362 17 F 41.2 1204
8 F 50.6 1502 18 M 51.9 1867
9 F 42.0 1256 19 M 46.9 1439
10 M 48.7 1614

  1. (a) Make a scatterplot of the data, using different symbols or colors for men and women.

  2. (b) Is the association between these variables positive or negative? What is the form of the relationship? How strong is the relationship?

  3. (c) Does the pattern of the relationship differ for women and men? How do the male subjects as a group differ from the female subjects as a group?