The shape of the distribution of the time required to get in oil change at a 15 minute oil change facility is unknown. However records indicate that the mean time is 16.2 minutes and the standard deviation is 3.3 minutes.
What is the probability that a random sample of n= 40 oil changes results in a sample mean time less than 15 minutes ? (Round 4 decimal places)
Suppose the manager agrees to pay each employee a $50 bonus if they meet a certain goal. On a typical Saturday the oil change facility will perform 40 oil changes between 10 AM and 12 PM. Treating this as a random sample there would be a 10% chance of the mean oil change time being at or below what value.
There is a 10% chance of being at or below or mean or oil change time of ______ minutes?