Draw a histogram for the following frequency distribution with unequal class length:

Class	$0-10$	$10-20$	$20-40$	$40-70$	$70-100$
Frequency	$15$	$13$	$28$	$36$	$27$

(N/A) To draw a histogram for a frequency distribution with unequal class lengths,we must calculate the adjusted frequency (height of the rectangle) for each class.
$1$. The formula for adjusted frequency is: $\text{Adjusted Frequency} = \frac{\text{Minimum class size}}{\text{Class size}} \times \text{Frequency}$.
$2$. The minimum class size is $10$ (from $0-10$ and $10-20$).
Calculation table:

Class	Frequency	Class Size	Adjusted Frequency
$0-10$	$15$	$10$	$(10/10) \times 15 = 15$
$10-20$	$13$	$10$	$(10/10) \times 13 = 13$
$20-40$	$28$	$20$	$(10/20) \times 28 = 14$
$40-70$	$36$	$30$	$(10/30) \times 36 = 12$
$70-100$	$27$	$30$	$(10/30) \times 27 = 9$

Finally,plot the class intervals on the $x$-axis and the adjusted frequencies on the $y$-axis to draw the histogram.