A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1485 and the standard deviation was 315. The test scores of four students selected at random are 1900, 1220, 2200, and 1370. Find the Z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1900 is 3 (Round to two decimal places as needed.)