Given a sample of n = 250 and x-bar of 130, and

a population standard deviation of o- = 8. Find the 95% confidence interval for the

population mean.

95% CI = [ __________ , __________ ]

2. Refer to pages 353 and 354 in the textbook.

1. The tail probability cut off by a critical value with confidence level C is __________.

Complete the following table.

Confidence level C b. 90% c. 95% d. 99%

Critical value z* _____ _____ _____

1. The formula for the confidence interval for the mean of a normal population is

____________________

3. Refer to Example 14.3 in the textbook.

1. Find the 90% confidence interval for the population mean.

90% CI = [ __________ , __________ ]

1. Find the 99% confidence interval for the population mean.

99% CI = [ __________ , __________ ]