An aptitude test known as the Gesell adaptive score test is given to children to measure their level of cognitive development. It is of interest to know whether or not a relationship exists between this test score and the age (in months) at which a child speaks his/her first word. To examine this, the following data were collected for 21 children: (a) Treating the Gesell score as the response variable (y) and the age at first word as the explanatory variable (x), make a scatterplot of these data.
Does there appear to be a linear relationship among these variables?