Ball bearing manufacturing is a highly precise business in which minimal part variability is critical. Large variances in the size of the ball bearings cause bearing failure and rapid wear-out. Production standards call for a maximum variance of .0001 inches. Gerry Liddy has gathered a sample of 15 bearings that shows a sample standard deviation of .014 inches. Use ɑ = .10
a. Please determine whether the sample indicates that the maximum acceptable variance is being exceeded.
b. What is the p value?
- The grade point averages of 352 students who completed a college course in financial accounting have a standard deviation of .940. The grade point averages of 73 students who dropped out of the same course have a standard deviation of .797.
a. Do the data indicate a difference between the variances of grade point averages for students who completed a financial accounting course and students who dropped out?
b. Use ɑ = .05 level of significance.
c. What is the p value?
Sample Solution
