Load library $($DAAG$)$ in R system and attach the "hills" dataset.

a$)$ Compute the median and the coefficient of variation for each variable in the data set.

b$)$ Write the $R$ command to select the variable climb where the data of less than or to $2000$

should be excluded.

c$)$ Use the R command to arrange the selected data set in part $($a$)$ according to the variable dist in

descending order.