Question

I dont understand the question

Answer 1

8.

Explanation:

This diagram is a histogram where the areas of the rectangles give the number of fish.

For example, the number of fish in the first rectangle (that is fish whose length is 0-10) is 10 * frequency density

= 10 * 0.6 = 6 fish.

So, the number of length 30 - 40 cm

= (40-30) * 0.8

= 10*0.8

= 8.