Probability based on normal distribution.
See attached file.
The length of time to complete a a full service oil change is normally distributed with a mean of 15.8 minutes with a standard deviation of 2.2 minutes.
Refer to table 4A megastat output attached.
A) Analyze the output determine what percentage complete full oil change will fall between 15 and 21 minutes
B) What percentage of complete full oil change will take less than 11 minutes? If 1000 cars have oil change how many do you ecpect to finish in less than 11 minutes?