Question

# A random sample of 15 adult male wolves from the Canadian Northwest Territories gave an average...

A random sample of 15 adult male wolves from the Canadian Northwest Territories gave an average weight x1 = 96.0 pounds with estimated sample standard deviation s1 = 7.5 pounds. Another sample of 27 adult male wolves from Alaska gave an average weight x2 = 89.0 pounds with estimated sample standard deviation s2 = 7.5 pounds. (a) Categorize the problem below according to parameter being estimated, proportion p, mean μ, difference of means μ1μ2, or difference of proportions p1p2. Then solve the problem.

1 μ1μ2

2p

3    μ

4 p1p2

(b) Let μ1 represent the population mean weight of adult male wolves from the Northwest Territories, and let μ2 represent the population mean weight of adult male wolves from Alaska. Find a 90% confidence interval for μ1μ2. (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 the 90% 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?

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

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

We can not make any conclusions using this confidence interval.

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

(A) we are find the mean difference for Alaskan wolve and Canadian wolves.

so, point estimate =

(B) Using TI 84 calculator

press stat then tests then 2-sampTInt

enter the data

Pooled: yes

C-level = 0.90

press ENTER

lower limit = 2.9

upper limit = 11.1

(C) Since the confidence interval is calculated for mean of Canadian wolves minus the mean of Alaska wolves and we get positive limits for the confidence interval

this means that the mean for canadian wolves is greater than mean for Alaska wolves

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

#### Earn Coins

Coins can be redeemed for fabulous gifts.