4. In addition to color and clarity, the independent certification group (GIA, HRD, or IGI) and the number of carats were recorded for each of 308 diamonds for sale on the open market. a. Use a histogram to describe the carat distribution of all 308 diamonds. b. Use a histogram to describe the carat distribution of diamonds certified by the GIA group. c. Repeat part (b) for the HRD and IGI certification groups. d. Compare the three carat distributions, parts b and c , Is there one particular certication group that appears to be assessing diamonds with higher carats that the others