# Question

A random sample of 10 items is drawn from a population whose standard deviation is unknown. The sample mean is x-bar = 270 and the sample standard deviation is s = 20. Use Appendix D to find the values of Student's t.

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

b. Repeat part a assuming that n = 20.

c. Repeat part a assuming that n = 40.

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 = 20.

c. Repeat part a assuming that n = 40.

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

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