1. Consider the following data frame "newdafr" and answer the following. X6 X7 X8 X9 X10 55 50 69 38 NA 14 18 7 6 79 NA 20 NA NA 37 NA 76 NA 12 NA 13 6 NA 17 4 65 36 55 64 45 43 54 8 33 65 73 NA NA 13 NA 59 76 2 10 68 50 70 NA 75 (a) Write the output of following command - which(is.na(newdaft)) (2M) (b) What is the output of the function !complete cases(newdafu) (2M) (c) Write command to fill the missing values in the column "x9" with the median of remaining values. (d) Write a command to replace the missing values in 10th row with 55 (2M) (e) Use functions to display the rows with missing values (2M)