# Question

A random sample of 25 items is drawn from a population whose standard deviation is known to be σ = 40. The sample mean is x-bar = 270.

a. Construct an interval estimate for with 95 percent confidence.

b. Repeat part a assuming that n 5 50.

c. Repeat part a assuming that n 5 100.

d. Describe how the confidence interval changes as n increases.

a. Construct an interval estimate for with 95 percent confidence.

b. Repeat part a assuming that n 5 50.

c. Repeat part a assuming that n 5 100.

d. Describe how the confidence interval changes as n increases.

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