Need help with Question also, not sure what i am doing wrong.

Question 18 Not yet answered Points out of 5.00 '7 Flag question Let x be a random variable representing dividend yield of Australian bank stocks. We may assume that x has a normal distribution with 0' = 11%. A random sample o_f 20 Australian bank stocks has a sample mean of x = 146%. For the entire Australian stock market, the mean dividend yield is A\" = 64%. Do these data indicate that the dividend yield of all Australian bank stocks is higher than 6.4%? Find (or estimate) the P- value. Round your answer to three decimal places. Select one: a. 0.494 b. 0.006 c. 0.012 cl. 0.024 9. 1.976 00000