# Question: a The mean of a sample of 25 was calculated

a. The mean of a sample of 25 was calculated as x̄ = 500. The sample was randomly drawn from a population with a standard deviation of 15. Estimate the population mean with 99% confidence.

b. Repeat part (a) changing the population standard deviation to 30.

c. Repeat part (a) changing the population standard deviation to 60.

d. Describe what happens to the confidence interval estimate when the standard deviation is increased.

b. Repeat part (a) changing the population standard deviation to 30.

c. Repeat part (a) changing the population standard deviation to 60.

d. Describe what happens to the confidence interval estimate when the standard deviation is increased.

**View Solution:**## Answer to relevant Questions

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