Final answer:
A bar graph is the most appropriate data display for comparing car colors to each other and to the total number of cars purchased.
Step-by-step explanation:
The most appropriate data display for comparing the most popular car colors to each other and to the total number of cars purchased would be a bar graph.
A bar graph displays data using rectangular bars of different heights, where the length of each bar represents the quantity or frequency of data. In this case, each car color (Red, Blue, Black, White) would have its own bar, and the height of each bar would correspond to the number of cars purchased in that color.
By comparing the heights of the bars, you can easily see which car colors are the most popular and how they compare to each other and to the total number of cars purchased.