The ratmaze.dat (https://sites.stat.psu.edu/online/courses/stat482/final/ratmaze.dat) data file contains data on the speed with which rats can negotiate a maze. The rats are grouped into three age groups (3, 6, and 9) and two genetic strains (A and B).
- Read the datadirectly from the fileinto a temporary SAS data set calledratmaze.
- Conduct a two-way analysis of variance withageandstrainas the predictor variables andspeedas the response variable. Be sure to include the interaction term betweenageandstrainin the model.
- Use the GPLOT procedure to create an interaction plot with average speedon the vertical axis andageon the horizontal axis.
Discuss the results. Specifically, does there appear to be an interaction between age and strain? Justify your answer in two ways: (1) using the output from the analysis of variance, and (2) using the interaction plot.