Question

(a) A sample of 25 male emperor penguins has a sample mean weight of 53.1 pounds and a sample standard deviation of 6.6 pounds. Assuming normality, find a 90 percent confidence interval for the population average weight of male emperor penguins.

(b) Another sample of 20 emperor penguins (from a different part of the antartica continent) has a sample mean weight of 48.8 pounds and a sample standard deviation of 8.2 pounds. Assume normality and equal variance and test, at a 5 percent level, whether the two samples are taken from emperor penguin populations with equal average weights.

	1.	a) CI = (50.8, 55.4)       b) we reject equality of the two means
	2.	a) CI = (50.9, 55.3)      b) we reject equality of the two means
	3.	a) CI = (50.9, 55.3)      b) we accept equality of the two means
	4.	a) CI = (50.8, 55.4)      b) we accept equality of the two means

explain your answer

Answer 1

Solution

a)

a 90 percent confidence interval for the population average weight of male emperor penguins is

a) CI = (50.8, 55.4)

b)

Conclusion : we accept equality of the two means