A standardized exam's scores are normally distributed. In a recent year, the mean test score was 1545 and the standard deviation was 316. The test scores of four students selected at random are 1940, 1260, 2260, and 1440. Find the z-scores that correspond to each value and determine whether any of the values are unusual. The z-score for 1940 is nothing. (Round to two decimal places as needed.)