Let x be a random variable representing dividend yield of bank stocks. We may assume that x has a normal distribution with = 1.9%. A random sample of 10 bank stocks gave the following yields (in percents). 5.7 ,4.8 ,6.0 ,4.9 ,4.0 ,3.4 ,6.5 ,7.1 ,5.3 ,6.1 Sample mean x=5.38 . Mean divided yield is u=4.6 and use a=.01 ..