Introduction to Prediction (2 of 3)
The scatterplot to below
shows the relationship between the Identical Blocks Test (a measure of spatial
ability) and the Wonderlic Test (a measure of general intelligence). As you can
see, the relationship is fairly strong:
The best fitting straight line is also shown.
It has a slope of 0.481 and a Y intercept of 15.8468. (Click here
see how to compute the slope and intercept and the criterion for deciding
best fit.) The regression line can be used for predicting. From the
graph, one can estimate that the score on the Wonderlic for someone
scoring 10 on Identical Blocks is about 20.
From the formula for Y', it can be calculated that the predicted
predicted score is 0.481 x 10 + 15.86 = 20.67.