A fashion student was interested in factors that predicted the salaries of catwalk models. She collected data from 231 models (supermodel.sav). For each model she asked them their salary per day (salary), their age (age), their length of experience as models (years) and their industry status as a model as reflected in their percentile position rated by a panel of experts (beauty). Use a linear model to see which variables predict a model’s salary. How valid is the model?