Answer Happy

7. A consumer electronics company is comparing the brightness of two different types of picture tubes for use in its television sets. Tube type A has mean brightness of 100 and standard deviation of 20, and tube type B has unknown mean brightness, but the standard deviation is assumed to be identical to that for type A. A random sample of n = 25 tubes of each type is selected, and X - XA is computed. If μB equals or exceeds μA, the manufacturer would like to adopt type B for use. The observed difference is XB - XA = 3.0. a) What is the probability that b) Is there strong evidence that exceeds by 3.0 or more if μg and are equal? is greater than ? HINT: Determine the distribution of mB-mA if mB=mA, then find the probability XB X₂ (use the z-score) that B exceeds A by 3.0 or more.