Techniques to be learned in Chapter 7 : Based on sample statistics given in the original problem, make an estimate of the population parameter using a confidence interval.

The parameters to be estimated are

7-2 proportion p

7-4 mean μ

7-5 standard deviation σ

At this point it is important to briefly review the relationship between samples and populations and the importance of proper sampling techniques.

Sampling must be done correctly if good results are to be obtained. We must choose a practical sample that will be representative of the population as a whole.

A representative sample will allow us to use sample statistics to make estimates of important population parameters. In this type of sample every member of the population has an equal chance of being included.

Simple random sampling is the type of sampling that is easiest to work with and usually the hardest to obtain. The techniques in chapter 7 are valid for simple random sampling and we will assume simple random sampling was performed in all problems we solve.