A random sample of18adult male wolves from the Canadian Northwest Territories gave an average weightx₁=99.0pounds with estimated sample standard deviations₁=6.2pounds. Another sample of25adult male wolves from Alaska gave an average weightx₂=89.6pounds with estimated sample standard deviations₂=7.4pounds.

(a) Categorize the problem below according to parameter being estimated, proportionp, mean, difference of means₁-₂, or difference of proportionsp₁-p₂. Then solve the problem.

a. p₁-p₂

b. p

c. ₁-₂

d.

(b) Let₁represent the population mean weight of adult male wolves from the Northwest Territories, and let₂represent the population mean weight of adult male wolves from Alaska. Find a99%confidence interval for₁-₂. (Use 1 decimal place.)

lower limit______

upper limit_____

(c) Examine the confidence interval and explain what it means in the context of this problem. Does the interval consist of numbers that are all positive? all negative? of different signs? At the99%level of confidence, does it appear that the average weight of adult male wolves from the Northwest Territories is greater than that of the Alaska wolves?

A. Because the interval contains only positive numbers, we can say that Canadian wolves weigh more than Alaskan wolves.

B. Because the interval contains both positive and negative numbers, we can not say that Canadian wolves weigh more than Alaskan wolves.

C. We can not make any conclusions using this confidence interval.

D. Because the interval contains only negative numbers, we can say that Alaskan wolves weigh more than Canadian wolves.