Confidence Intervals.

1. It is often difficult to find the exact mean average of a large population of data. We use
confidence Intervals to estimate where we think the true mean lies. Discuss the advantages of
using a confidence interval.
Give an example of a large population of data that is suited to a confidence interval estimate- in
other words, it would be very hard to find the exact true mean of the data.
2. Estimate Confidence Interval for Population Mean based on sample data and
using Appendix Table for t-Distribution
(population standard deviation is not known, but sample standard deviation is given).
Keep Confidence Level 90%
For example size n, choose the value for n between 4 and 10
For sample mean – x, choose a value between 10 and 80
For sample standard deviation s, choose a value between 3 and 20
1. Use appendix table IV and t-value for your case
2. Calculate margin of error ;
3. Create Confidence Interval for Population Mean