A radio station claims that the amount of advertising each hour has a mean of 16 minutes and a sample variance of 1.9 minutes. You listen to the radio sta- tion for 1 hour and observe that the amount of adver- tising time is 14 minutes. Calculate the z-score for this amount of advertising time. (a) 1 (b) 1.05 (c) -1.05 (d) -1.45 (e) 2.11