A large oil company is studying the number of gallons of gasoline purchased per customer at self-service pumps. the mean number of gallons is 8 with a standard deviation of 3 gallons. the median is 10.75 gallons. what is the pearson's coefficient of skewness?rev: 03_01_2013_qc_27450+ 2.75+ 1.00−1.00−2.75