The article "Evaluating the BOD POD for Assessing Body Fat in Collegiate Football Players" (Medicine and Science in Sports and Exercise, 1999: 1350-1356) reports on a new air displacement device for measuring body fat. The customary procedure utilizes the hydrostatic weighing device, which measures the percentage of body fat by means of water displacement. Here is representative data read from a graph in the paper.

a. Use various methods to decide whether it is plausible that the two techniques measure on average the same amount of fat.
b. Use the data to develop a way of predicting an HW measurement from a BOD POD measurement, and investigate the effectiveness of such predictions?

BOD 2.5 4.0 4. 6.2 7.1 7.0 8.3 9.2 9.3 12.0 12.2 HW 8.0 6.2 9.2 6.4 8.6 12.2 7.2 12.0 14.9 12.1 15.3 BOD 12.6 14.2 144 15. 15.2 16.3 17.1 179 17.9 HV 14.8 14.3 16.3 17.9 19.5 17.5 14.3 18.3 16.2