For the given situation, write what you think the best nonlinear transformation to the variables would be to investigate this change. answer in the form of a regression model.

• a. In investigating the effect of IQ on salary, we'd like to see the effect in terms of an elasticity.
• b. We'd like to see how age affects salary. We'd like to investigate whether there is some peak effect of age on salary.
• c. We'd like to investigate whether there is a differential/heterogeneous effect on age across genders.