27. Replace NA value in work column in row 4 (Michael's work) with 12. 28. Calculate the average age - ignore the NA values in the calculation 29. Replace the NA value in age in row 4 (Michael's age) with the average age value (calculated in 23) 30. Omit all other observations with missing values (NA). Note that this will remove all rows containing the missing data. Assign the revised data (without NA data) to a new data frame empComplete 31. Display empComplete