23. Siegel (1990) found that elderly people who owned dogs were less likely to pay visits to their doctors after upsetting events than were those who did not own pets. Similarly, consider the following hypothetical data. A sample of elderly dog owners is compared to a similar group (in terms of age and health) who do not own dogs. The researcher records the number of visits to the doctor during the past year for each person. The data are as follows:

Control Group Dog Owners 10 7 8 4 7 9 9 3 13 7 7

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a. Is the number of doctor visits significantly lower for the dog owners than for participants in the control group? Use a one-tailed test will  .05.

b. Compute the value of r 2 (percentage of variance accounted for) for these data.