(Solved): 2. Suppose that the mean checkout time for an express checkout lane in a supermarket is 2.5 minutes ...

2. Suppose that the mean checkout time for an express checkout lane in a supermarket is 2.5 minutes with the standard deviation of 1.2 minutes. 2.1) Find the probability that the total checkout time of the next 16 customers (regarded as a random sample) is less than 0.5 hour. 2.2) With 85% chance, how long do you think for the checkout time of 16 customers?