Two labs produce 1280 1024 LCD displays. At random, records are examined for 12 independently chosen hours of production in each lab, and the

Two labs produce 1280 × 1024 LCD displays. At random, records are examined for 12 independently chosen hours of production in each lab, and the number of bad pixels per thou- sand displays is recorded.
(a) Assuming equal variances, at the .01 level of significance, is there a difference in the defect rate between the two labs? State your hypotheses and show all steps clearly.
(b) At the .01 level of significance, can you reject the hypothesis of equal variances? State your hypotheses and show all steps clearly.

Defects in Randomly Inspected LCD Displays Lab A 422, 319, 326, 410, 393, 368, 497, 381, 515, 472, 423, 355 Lab B 497, 421, 408, 375,410, 489, 389,418 447, 429,404. 477