Question

how does tge procedure of drawing a histogram differ when class intervals are unequal in comparision to equal class intervals in a frequency tables​

Answer 1

When constructing a histogram with non-uniform (unequal) class widths, we must ensure that the areas of the rectangles are proportional to the class frequencies.

Remember that the histogram differs from a bar chart in that it is the area of the bar that denotes the value, not the height. This means that we would need to consider the widths in order to determine the height of each rectangle.