Chapter 14

14.1 The researchers are seeking to predict IQ from brain size. Thus, brain size is the explanatory variable. The response variable is IQ. The following figure is a scatterplot of the data.

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14.2 There is a weak positive association. There is no pronounced form other than evidence of a weak positive association. There are no outliers.

14.3 One might estimate the correlation to be about 0.3 or 0.4. The actual correlation is 0.38.