Mindy Fernandez is in charge of production at the new sport-utility vehicle (SUV) assembly plant that just opened in her town. Lately she has been concerned that the wheel lug studs do not match the chrome lug nuts close enough to keep the assembly of the wheels operating smoothly.Workers are complaining that cross-threading is happening so often that threads are being stripped by the air wrenches and that torque settings also have to be adjusted downward to prevent stripped threads even if the parts match up. In an effort to determine whether the fault lies with the lug nuts or the studs, Mindy decided to ask the quality-control department to test a random sample of 60 lug nuts and 40 studs to see if the variances in threads are the same for both parts.The report from the technician indicated that the thread variance of the sampled lug nuts was 0.00213 and that the thread variance for the sampled studs was 0.00166. What can Mindy conclude about the equality of the variances at the 0.05 level of significance?
a. Solve using the p-value approach.
b. Solve using the classical approach.