A standardized​ exam's scores are normally distributed. In a recent​ year, the mean test score was 21.3 and the standard deviation was 5.6. The test scores of four students selected at random are 13​,...

A standardized​ exam's scores are normally distributed. In a recent​ year, the mean test score was 21.3 and the standard deviation was 5.6. The test scores of four students selected at random are 13​, 22​, 9​, and 37. Find the​ z-scores that correspond to each value and determine whether any of the values are unusual. The​ z-score for 13 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 22 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 9 is nothing. ​(Round to two decimal places as​ needed.) The​ z-score for 37 is nothing. ​(Round to two decimal places as​ needed.) Which​ values, if​ any, are​ unusual? Select the correct choice below​ and, if​ necessary, fill in the answer box within your choice. A. The unusual​ value(s) is/are nothing. ​(Use a comma to separate answers as​ needed.) B. None of the values are unusual.