Explore BrainMass

Confidence Interval For Mean Price And Age Of Bank Employees

Please see attachment for data.

1. To find the confidence interval for the true mean of the "price in $000" of all the employees in the bank, should the z-score or t-score be used?if so why?

2. Find a 95% and a 99% confidence level for "price in $000" and "age" respectively using all the 80 data given that the population variance of the "price $000" is 25 million and for "age" is 81. Write a brief report on your findings.

3. From the 80 data, take any 20 data and find a 95% confidence interval for "price in $000" and "age" respectively. Report on your findings.


Solution Preview

Part 1. When the population variance is known, z-score is used to construct confidence intervals.
When the population variance is not known, t-score is used to construct confidence intervals.

It is important to note that, as ...

Solution Summary

This solution is comprised of detailed explanation on calculating confidence intervals. Also included is an explanation on when to use z-scores versus t-scores when calculating confidence intervals.