Chapter 7.3, Problem 6BSC

Finding Critical Values and Confidence Intervals. In Exercises 5–8, use the given information to find the number of degrees of freedom, the critical values ${\text{χ}}_{\text{L}}^2$ and ${\text{χ}}_{\text{R}}^2$, and the confidence interval estimate of σ. The samples are from Appendix B and it is reasonable to assume that a simple random sample has been selected from a population with a normal distribution.

6. Weights of Pennies 95% confidence; n = 37, s = 0.01648 g.