A chemical manufacturer purchases a particular material from two different suppliers. The mean level of impurities seems to be the same but the manufacturer is concerned about the variability in the level of impurities from shipment to shipment. Random samples are taken and the results are:
Supplier 1 Variance 0.273 n = 10
Supplier 2 Variance 0.094 n = 12
Do the sample data provide sufficient evidence to indicate a difference in the variability of shipment impurity levels for the two suppliers? Test using a = 0.01. Assume that the impurity levels for both suppliers are normally distributed