Please help me these questions. If it is feasible, please give me your calculations (formula...)Thanks so much

The highway miles per gallon of a sample of vehicles are as follows: 10, 12, 15, 13, 14, 15, 16, 17, 16, 17, 18, 20, 22, 24, 26,28, 27, 29, 30, 45. 8. the mean mile per gallon is: a. 15 b. 17.5 c. 20.7 9. The median mile per gallon is: : a. 15 b. 17.5 c. 20.7 10. The mean absolute deviation of this data set (miles per gallon) is; a. 0 b. - 6.54 c. 6.54 11. The standard deviation (miles per gallon) is: a. 10.0 b. 8.32 c. 8.12 12. The variance in (miles per gallon)2 is: a. 100.0 b. 65.9 c. 69.2 13. 25% of gas mileages (miles per gallon) in this data set fall above: a. 12.0 b. 15.0 c. 26.5 14. The range of the middle 50% of the data set is: a. 10.0 b. 11.5 c. 15.0 15. The above data set is: a. positively skewed, b. negatively skewed c symmetric