Answer:
40 people
Step-by-step explanation:
First thing, you have to find the area below the 40 - 55 line in the histogram. The area can be find using the area of a rectangle: side × side
Doing this you'll find an area of 60.
After that, find the total area of the histogram in the same way: separate it in rectangles and use the formula for the area of a rectangle, and after you'll find a total area of 100
Now you have to do a rule of three:
We know from the question statement that the amount of people with 40 - 55 years old is 25, and that area correspond to 60, so:
60 ------- 24
100 ------- x
60•x = 24•100
60x = 2400
x = 2400/60
x = 40
