A big toe problem. Table 7.4 (page 194) and Exercises 7.42 and 7.44 describe the relationship between two deformities of the feet in young patients. Metatarsus abductus (MA) may help predict the severity of hallux abducto valgus (HAV).

The paper that reports this study says, “Linear regression analysis, using the hallux abductus angle as the response variable, demonstrated a significant correlation between the metatarsus abductus and hallux abductus angles.”11 Do a suitable analysis to verify this finding. The study authors note that the scatterplot suggests that the variation in y may change as x changes, so they offer a more elaborate analysis as well.