To model the relationship between y, a dependent variable, and x, an indepcndent variable, a researcher has taken one measurement on y at each of three different x values. Drawing on his mathematical expertise, the researcher realizes that he can fit the The regression equation is Y = 90.1

- 1.84 X1 + .285 X2 Predictor Coef StDev t-ratio P Constant 90.10 23.10 3.90 0.002 XI -1.836 0.367 -5.01 0.001 X2 0.285 0.231 1.24 0.465 Analysis of Variance SOURCE DF S S MS F P Regression 2 14801 7400 64.91 0.001 Error 12 1364 114 Total 14 16165 second-order model Residual Plot for Exercise 10.48 A and it will pass exactly through all three points, yielding SSE = 0. The researcher, delighted with the "excellent" fit of the model, eagerly sets out to use it to make inferences. What problems will he encounter in attempting to make inferences?
Applying the Concepts