Let x be a random variable representing dividend yield of Australian bank stocks. We may assume that x has a normal distribution with a = 2.1%. A random sample of 13 Australian bank stocks has a sample mean of x = 8.78%. For the entire Australian stock market, the mean dividend yield is & = 5.7%. Do these data indicate that the dividend yield of all Australian bank stocks is higher than 5.7%? Use a = 0.01. What is the value of the test statistic? O 0.407 O - 1.467 5.288 O - 5.288 O - 0.407