The Grades of a Sample of 10 Students, Selected at Random

Short Answer

The grades of a sample of 10 students, selected at random from a large population, are 71, 86, 75, 63, 92, 70, 81, 59, 80, and 90.
Compute the sample variance.
______________
Construct a 90% confidence interval estimate for the population variance.
______________
Construct a 90% confidence interval estimate for the population standard deviation.
______________
Can we infer at the 90% confidence that the population variance is significantly less than 100?
Test statistic = ______________
Critical Value(s) = ______________
Conclusion: ______________
Interpretation: __________________________________________