The accompanying data set contains two variables, Date1 and Date2. 

a. Create a new variable called “DifferenceInYear” that contains the difference between Date1 and Date2 in year for each observation. What is the average difference in year? 

b. Create a new variable called “Month” that contains the month values extracted from Date1. What is the average month value? 

c. Bin the month values in four equal-interval groups. Label the groups using numbers 1 (lowest values) to four (highest values). Which group has the highest number of observations?