Midterm 1. A lumber company wants to estimate board feet of lumber from black cherry trees based on their height. They plan to harvest equal numbers of cherry trees at heights of 30’, 40’, 50’ and 60’. A pilot study showed a strong linear trend with hints of curvilinearity, and the company wants to be able to test whether a quadratic regression model would be more appropriate than a simple linear model to predict board feet. Suppose the contrast coeﬃcients for the quadratic contrast L Q are (1 ,-1 ,-1 , 1) and the company would like to detect L Q /σ = 2 with probabilty .9. How many trees of each height should be harvested? Assume α = . 05. 2. Members of the Native Plant Society and the Hemerocallis Society organize teams to plant Rocky Shoals Spider Lilies in the Broad River. Four diﬀerent methods of planting comprise all combinations of Depth (6”,9”) and Planting Material (Gravel,Sand). Each group used 4 distinct teams of members and planted 100 bulbs over 4 separate days
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This note was uploaded on 10/01/2009 for the course STAT stat706 taught by Professor Johnm.grego during the Spring '08 term at South Carolina.