The accompanying data file contains three variables, x1, x2, and x3. Click here for the Excel Data File a. Bin the values of x into three equal-size groups. Label the groups with numbers 1 (lowest values) to 3 (highest values). How many observations are assigned to group 2? Number of observations assigned to group 2 b. Bin the values of x2 into three equal-interval groups. Label the groups with numbers 1 (lowest values) to 3 (highest values). How many observations are assigned to group 3? Number of observations assigned to group 3 c. Bin the values of xy into the following three groups: <50,000, between 50,000 and 100,000, and > 100,000. Label the groups with numbers 1 (lowest values) to 3 (highest values). How many observations are assigned to group 3? Number of observations assigned to group 3