The accompanying data set contains three variables, x₁, x₂, and x₃. 

a. Create a new variable called “Difference” that contains the difference between the values of x₁ and x₂ for each observation (i.e., x₂ − x₁). What is the average difference? 

b. Create a new variable called “PercentDifference” that contains the percent difference between the values of x₁ and x₂ for each observation (i.e., (x₂ − x₁)/x₁). What is the average percent difference? 

c. Create a new variable called “Log” that contains the natural logarithms for x₃. Bin the logarithm values into five equal-interval groups. Label the groups using numbers 1 (lowest values) to 5 (highest values). How many observations are in group 2?