1. Construct the confidence interval for the population mean . c=0.90, x=6.7, =0.6, and n=45. A 90% confidence interval for

is ( , ).

2. Find the critical value zc necessary to form a confidence interval at the level of confidence shown below for c=0.85.

3. You are given the sample mean and the population standard deviation. Use this information to construct the 90% and 95% confidence intervals for the population mean. Interpret the results and compare the widths of the confidence intervals. If convenient, use technology to construct the confidence intervals.A random sample of 45 home theater systems has a mean price of $150.00. Assume the population standard deviation is $16.60.

Construct a 90% confidence interval for the population mean.The 90% confidence interval is ( , )

4. Construct the indicated confidence interval for the population mean using the t-distribution. Assume the population is normally distributed.

c=0.95,

x=13.9,

s=4.0,

n=9