Skip over navigation
I need a figure for the fish population in a lake.
I catch 40 fish and mark a scale on each fish so that they can be identified if caught again.
The fish are then released and one week later I once more catch 40 fish and look to see which of these I caught before.
How does this help me come up with a figure for the fish population in a lake?
What assumptions does this method of estimating the fish population rely on?
How do you think you could improve the accuracy of your estimate?
Click here for a poster of this problem.
This resource is part of the collection Statistics - Maths of Real Life
Counting Fish
Age 14 to 16
Challenge Level 
I need a figure for the fish population in a lake.
I catch 40 fish and mark a scale on each fish so that they can be identified if caught again.
The fish are then released and one week later I once more catch 40 fish and look to see which of these I caught before.
How does this help me come up with a figure for the fish population in a lake?
What assumptions does this method of estimating the fish population rely on?
How do you think you could improve the accuracy of your estimate?
Click here for a poster of this problem.
This resource is part of the collection Statistics - Maths of Real Life
You may also like
There's a Limit
Explore the continued fraction: 2+3/(2+3/(2+3/2+...)) What do you notice when successive terms are taken? What happens to the terms if the fraction goes on indefinitely?
Not Continued Fractions
Which rational numbers cannot be written in the form x + 1/(y + 1/z) where x, y and z are integers?