Students Struggled With…

• The small amount of algebra needed to make a prediction using a nonlinear model.

• Providing several justifications why one nonlinear model is better than another.

• Interpreting regression computer output when the explanatory variable includes a log. 

Remedies…

• A logarithm is the inverse operation of an exponential (with any base). A natural log is the inverse operation of an exponential with base b. 

• There are several ideas that can be used to justify why one model is better than another: residual plots, r and r-squared,  and s.her

• When looking a regression computer output, pay careful attention to the variable listed under "constant" as it might include a logarithm.lre and find the area above it.