http://www.ck12.org Chapter 9. Regression and Correlation
Review Answers
- There are 3 predictor values – Test 1, Test 2 and Test 3.
- The regression coefficient of 0.5560 tells us that every 0.5560 percent change in Test 2 is associated with a
1 .000 percent change in the final exam when everything else is held constant. - From the data given, the regression equation isY= 0. 0506 X 1 + 0. 5560 X 2 + 0. 2128 X 3 + 10 .7592.
- TheR^2 value is 0.4707 and indicates that 47% of the variance in the final exam can be attributed to the variance
of the combined predictor variables. - Using the print out, we see that theFstatistic is 13.621 and has a correspondingpvalue of 0.000. This means
that the probability that the observedRvalue would have occurred by chance if it was not significant is very
small (slightly greater than 0.000) - Test 2. Upon closer examination, we find that only the Test 2 predictor variable is significantly significant
since thetvalue of 3.885 exceeds the critical value (as evidenced by the lowpvalue of.003). - No. It is not necessary to include Test 1 and Test 3 in the multiple regression model since these two variables
do not have a significant test statistic that exceeds the critical value.