Question: The time that it takes a realtor to lease an apartment is 2.3 months on average, with a std. deviation of 1.5 months. Find the probabilities that in a sample of 36 apartments, the average time it takes to lease an apartment is:

(a) At least 1.8 months

(b) From 2.0 to 2.5 moths

(c) Less than 2.2 months