Question: The price (in $) and the carat weight of a diamond are its two most known characteristics. In order to understand the role carat weight has in determining the price of a diamond, the carat weight and price of 20 loose round diamonds, all of color D and clarity VS1, were obtained recently as shown below.

Diamonds smaller than 0.50 carats and diamonds larger than 0.66 carats may not fit the linear pattern demonstrated by this data. Explain.