Explore BrainMass

Confidence Intervals, Sample Size, and Confidence Levels

1. Can you give a general rule as to what happens with confidence intervals as a function of sample sizes and confidence levels? What are the trade-offs?

2. Take a sample of something in your work environment, something simple, and calculate a confidence interval.

Some possible samples: the average number of people in your unit for the last few weeks; the average number of people in cars you pass on the freeway (be careful - maybe do this when carpooling); the average length of a phone call; the proportion of men vs women that you see in a day.

Does the confidence interval surprise you? Interpret it.

Solution Preview

Please see the attached document for a full solution.

1. Please see the example in the attachment.

N is sample size and z is confidence level.
A trade-off (or tradeoff) is a situation that involves losing one quality or aspect of something in return for gaining another ...

Solution Summary

This response defines and describes the relationship confidence intervals, samples sizes, and confidence levels.