Let x be a random variable representing dividend yield of bank stocks. We may assume that x has a normal distribution with ? = 2.5%. A random sample of 10 bank stocks gave the following yields (in...

Letx be a random variable representing dividend yield of bank stocks. We may assume thatx has a normal distribution with ? = 2.5%. A random sample of 10 bank stocks gave the following yields (in percents).

The sample mean is  = 5.38%. Suppose that for the entire stock market, the mean dividend yield is ? = 4.7%. Do these data indicate that the dividend yield of all bank stocks is higher than 4.7%? Use ? = 0.01.