In different scenarios, the data will be different. However, sometimes, it's impossible to draw a histogram with equal widths, so in order to maintain clarity and fairness, the area of the bars should actually be proportional to the frequency, which is usually the y-axis of the graph or height of the bars.
The answer would be a height o 18 inches. how you figure that is by taking the total cubic inches and divide by the base number which is 42 inches. 756 divided by 42 is 18. and to check your answer multiply. 18 times 42 equals 756.
