Xr14-64 Do medical specialists differ in the amount of time they devote to patient care? To answer this question, a statistics practitioner organized a study.

The numbers of hours of patient care per week were recorded for five specialists. The experimental design was randomized blocks. The physicians were blocked by age. (Adapted from the Statistical Abstract of the United States, 2000, Table 190.)

a. Can we infer that there are differences in the amount of patient care between medical specialties?

b. Can we infer that blocking by age was appropriate?