A food scientist wants to determine the optimal time and temperature for heating a frozen dinner. The scientist prepares 14 samples at various times and temperatures, and then has professional food tasters rate each sample for overall quality. The scientist creates a 3D scatterplot to examine the results.
Heating the dinner at shorter time intervals results in under-cooked product and low quality scores. However, heating at the longest intervals combined with the highest temperatures also results in low scores because the food becomes over-cooked. The optimal settings appear to be between 400° and 450° and between approximately 30 and 36 minutes.
Adding project lines helps you visualize each point's position in three-dimensional space. Rotate the graph to view the plot from different angles and explore possible relationships in the data. For more information, go to Viewing a 3D scatterplot.