12. Engineering: Roller Bearings Two processes for manufacturing large roller bearings are under study. In both cases, the diameters (in centimeters) are being examined. A random sample of 21 roller bearings from the old manufacturing process showed the sample variance of diameters to be s2 5 0.235.

Another random sample of 26 roller bearings from the new manufacturing process showed the sample variance of their diameters to be s2 5 0.128. Use a 5% level of significance to test the claim that there is a difference (either way)

in the population variances between the old and new manufacturing processes.