Question

Salmon: Assume that the weights of spawning Chinook Salmon in the Columbia River are normally distributed with a population standard deviation (σ) of 4.5 pounds. You randomly catch and weigh 20 such salmon. The mean weight from your sample is 25.2 pounds. We did this problem earlier in this problem set while assuming that the sample standard deviation was 4.5 pounds. We now assume the population standard deviation is 4.5 pounds.

(a) Test the claim that the mean weight of Columbia River salmon is greater than 23 pounds. Use a 0.10 significance level.

(b) Test the same claim at the 0.05 significance level.

(c) Test the same claim at the 0.01 significance level.

(d) We did similar tests in problem # 18 only we did not know the population standard deviation. How do the results from that problem compare to the results obtained in this problem?

Answer 1