Blackbutt Architectural Premium Timbers harvest trees from their blackbutt plantations, and process these in response to orders they receive from builders for premium timber. The current process of selecting trees for harvest is wasteful. Sometimes they take more trees than they need, meaning that they miss out on extra growth opportunities for any tree prematurely harvested. Sometimes they don't take enough trees meaning they have to perform costly re-work. They need a way to easily predict the timber yield from a tree. A visiting expert suggests that they should be able to predict the yield from a tree by measuring its CBH (Circumference measured at Breast Height). To test this idea, they harvest and process a random sample of 29 trees. The data is captured in the table below.