The waiting time at Dunkin Donuts has a mean of 2.3 minutes and a standard deviation of 0.6 minutes. The waiting time at Honey Dew Donuts has a mean of 1.9 minutes and a standard deviation of 0.9. Diane went to Dunkin Donuts and waited in line for 2.6 minutes. Hailey went to Honey Dew Donuts and waited 2.4 minutes. 

(a) Find the z-score for Diane: ________ 

(b) Find the z-score for Hailey: ________

(c) Who had the shortest waiting time relatively to the experience of other customers in the same donut shop