4. Diamonds are categorized according to the "four Cs": carats, clarity, color, and cut. Each diamond stone that is sold on the open market is provided a certificate by an independent diamond assessor that lists these characteristics. Data for 308 diamonds were extracted from Singapore's Business Times and are saved in the DIAMONDS file. Color is classified as as D, E, F, G, H, or I, while clarity is classified as IF, VVS1 VVS2, VS1, or VS2. Use a graphical technique to summarize the color and clarity of the 308 diamond stones. What is the color and clarity that occurs most often? Least often?