Two models of batteries are measured for their discharge time (in hours): ModelA 5.5 5.6 6.3 4.6 5.3 5.0 6.2 5.8 5.1 5.2 5.9 ModelB 3.8 4.3 4.2 4.0 4.9 4.5 5.2 4.8 4.5 3.9 3.7 4.6 Assume that the discharge times of Model A follows a normal distribution NW1, 0%), and the discharge times of Model B follows a normal distribution N012, 0%). (a) Suppose the variances from the two models are the same, at signicant level 04 : 0.01, can we assert that Model A lasts longer than Model B? (b) At a : 0.05, test if the two samples have the same variance