Question 1:

a) A random sample of 25 was drawn from a normal distribution whose standard deviation is 5. The sample mean is 80. Determine the 95% confidence interval estimate of the population mean.

b) Repeat part a with a sample size of 100

c) Repeat Part a with a sample size of 400

d) Describe what happens to the conference interval estimate when the sample size increases.

Question 2:

a) A statistics practitioner randomly sampled 100 observations from a population whose standard deviation is 5 and found that x(absolute value) is 10. Estimate the population mean with 90% confidence.

b) Repeat Part a with a sample size of 25.

c) Repeat part a with a sample size of 10.

d) Describe what happens to the confidence interval estimate when the sample size decreases.