Question

To compute the necessary sample size for an interval estimate of a population mean, all of the following procedures are recommended when is unknown except

a. use the sample standard deviation from a preliminary sample.
b. use judgment or a best guess.
c. use 0.5 as an estimate.
d. use the estimated from a previous study.

Answer 1

One of the procedures that is not recommended when the population standard deviation is unknown is to use the sample standard deviation from a preliminary sample.

Step-by-step explanation:

In the case where the population standard deviation (σ) is unknown, several procedures are recommended to compute the necessary sample size for an interval estimate of a population mean.

However, one of the procedures that is not recommended is to use the sample standard deviation from a preliminary sample.

Using the sample standard deviation from a preliminary sample is only recommended when the population standard deviation is known.