Name: __________________________________

“Transformations to Achieve Linearity”

(Take-home portion of 11/15/2011 STAtistics test)

Consider the following data set:

x y

.2         1.2
            .4         1.3
            .8         1.4
            1.2       1.5
            1.5       1.55
            1.9       1.6
            1.95     1.6
            2.2       1.6
            2.3       1.61
            2.5       1.62
            3          1.64

11. Is a linear fit appropriate? Justify your answer.

12. Two fits are being considered: a linear fit of log x to y³, and a linear fit of log x to log y. Which fit is more appropriate, and why? Justify your answer with a scatterplot and two residual plots. Use reverse side if necessary.

13. For the fit that you chose in #12, compute the equation for  Then use your equation to estimate y when x = 0.92.

14. Can your model in #13 be used to predict y when x = 3.3? Why or why not?