You want to estimate for the population of IQ scores of statistics professors. Find the minimum

Question:

You want to estimate σ for the population of IQ scores of statistics professors. Find the minimum sample size needed to be 95% confident that the sample standard deviation s is within 1% of σ. Is this sample size practical?

Assume that each sample is a simple random sample obtained from a normally distributed population. Use Table 7-2 on page 338 to find the indicated sample size.

Table 7-2: