# Confidence interval for mean

* The UNITE/MORI 2004 survey of student experiences estimated that university students in the UK paid on average $54 per week in accommodation costs.

Assume that this average is based on a sample 755 students and that the population standard deviation for weekly accommodation costs is $ 11.

a. Construct a 90 per cent confidence interval estimate of the population mean.

b. Construct a 95 per cent confidence interval estimate of the population mean.

c. Construct a 99 per cent confidence interval estimate of the population mean.

d. Discuss what happens to the width of the confidence interval as the confidence level is increased. Does this result seem reasonable? Explain.

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Inquiry

* The UNITE/MORI 2004 survey of student experiences estimated that university students in the UK paid on average $54 per week in accommodation costs.

Assume that this average is based on a sample 755 students and that the population standard deviation for weekly accommodation costs is $ 11.

The confidence interval for population mean is given by

Tune

a. Construct a 90 per cent confidence interval estimate of the population mean.

Confidence Interval Estimate for the Mean

Data

Population Standard Deviation 11

Sample ...

#### Solution Summary

This solution provides step-by-step details of calculation of confidence interval for mean. Interactive Excel sheet is included. The user can edit the inputs and obtain the complete results for a new set of data.