In the production of printed circuit boards, errors in the alignment of electrical connections are a source of scrap. The data in the file Registration Error-High Cost contains the registration error and the temperature used in the production of circuit boards in an experiment in which higher cost material was used. (Data extracted from C. Nachtsheim and B. Jones, "A Powerful Analytical Tool," Six Sigma Forum Magazine, August 2003, pp. 30-33.)
a. Construct a scatter plot for temperature and registration error.
b. Fit a quadratic regression model to predict registration error and state the quadratic regression equation.
c. Perform a residual analysis on the results and determine whether the regression model is valid.
d. At the 0.05 level of significance, is there a significant quadratic relationship between temperature and registration error?
e. At the 0.05 level of significance, determine whether the quadratic model is a better fit than the linear model.
f. Interpret the meaning of the coefficient of multiple determinations.
g. Compute the adjusted r2.