What does Figure 2.16 imply (if anything) about the effect of whether the mother smoked or not on birthweight? It might help to answer this question if the values in the cross‐tabulation were...

What does Figure 2.16 imply (if anything) about the effect of whether the mother smoked or not on birthweight? It might help to answer this question if the values in the cross‐tabulation were expressed as percentages of the columns. Try this and see if it helps.