Question

You want to be​ 95% confident that the sample standard deviation is within​ 40% of the population standard deviation. Find the appropriate minimum sample size

. A. 144 B. 21 C. 12 D. 22

Answer 1

To be 95% confident that, "s" is within of the value of sigma	1%	5%	10%	20%	30%	40%	50%
The sample size n should be at least	19205	768	192	48	21	12	8
To be 95% confident that, "s" is within of the value of sigma	1%	5%	10%	20%	30%	40%	50%
The sample size n should be at least	33218	1336	336	85	38	22	14

Using above table we get, sample size for 95% confidence level and sample standard deviation is within 40% of the population standard deviation is 12

Therefore, required sample size is 12