Basic Statistics - Mean and Standard Deviation (population). Following are the historical returns for Cool Hill Ski Resort. 201612% 20178% 201812% (negative) 201916% 20207.5% Based on the above listed information, what is the average and standard deviation for this data set (or,,,what is the expected return in 2021) 7.3% average and 12.65% population standard deviation 7.3% average and 2.65% population standard deviation 6.3% average and 9.65% population standard deviation 5.3\% average and 10.65% population standard deviation