With reference to Exercise 11.36, construct a 90% confidence interval for the ratio of the variances of the two populations sampled.
In exercise
The following are the heat- producing capacities of coal from two mines (in millions of calories per ton):

Assuming that the data constitute independent random samples from normal populations with equal variances, construct a 99% confidence interval for the difference between the true average heat-producing capacities of coal from the two mines.

Transcribed Image Text:

Mine A: 8,500. 8,330. 8,480, 7,960. 8,030 Mine B: 7,710. 7,890. 7,920, 8,270. 7860