9.12 Refer to Exercise 7.20. The wildlife biologist was interested in determining if the mean weights of deer raised in a zoo would be lower than those from a more uncontrolled environment, for example, either from the wild or raised on a ranch.

a. Use a multiple comparison procedure to determine if the mean weight of the deer raised in the wild or on a ranch is significantly higher than the mean weight of deer raised in a zoo.

b. Write a linear contrast to compare the average weight of deer raised in a zoo or on a ranch to the mean weight of deer raised in the wild.

c. Test at the  a = .05 level if your contrast in (b) is significantly different from zero. What conclusions can you make from this test?

Exercise 7.20

7.20 A wildlife biologist was interested in determining the effect of raising deer in captivity on the size of the deer. She decided to consider three populations: deer raised in the wild, deer raised on large hunting ranches, and deer raised in zoos. She randomly selected eight deer in each of the three environments and weighed the deer at age 1 year. The weights (in pounds) are given in the following table.

 

a. The biologist hypothesized that the weights of deer from captive environments would have a larger level of variability than the weights from deer raised in the wild. Do the data support her contention?

b. Are the requisite conditions for the test you used in (a) satisfied in this situation? Provide plots to support your answer.