Assume that each sample is obtained by randomly selecting values from a population with a normal distribution.
Refer to Data Set 21 in Appendix B.
a. Use the range rule of thumb (see Section 2-5) to estimate σ, the standard deviation of values for the "depth" of high-price diamonds.
b. Use the listed weights to construct a 98% confidence interval for σ.
c. Does the confidence interval contain your estimated value for σ?