Question

7.3.19 Question Help * Assume that the sample is a simple random sample obtained from a normally distributed population of IQ scores of statistics professors. Use the table below to find the minimum sample size needed to be 99% confident that the sample standard deviation s is within 40% of ?. Is this sample size practical? To be 95% confident that s is within | 1% | 5% | 10% | 20% | 30% | 40% | 50% | of the value ofo, the sample size n should be at least To be 99% confident that s is within | 1% | 5% | 10% | 20% | 30% | 40% | 50% | of the value of ?, the sample size n |33,218| 1,336 | 336 | 85 | 38 | 22 should be at least |19,205| 768 | 19 2 482112 8 The minimum sample size needed is

Answer 1

from below table in 99% confidence interval category ; for s is within 40% of $\sigma$ ; sample size required is 22.

hence minimum sample size needed is 22