Capture Recapture

Which one of these is a correct assumption you need to make about a population between samplings?

• It is a closed population

• It won't rain between samplings

• There are lots of deaths

• There are lots of births

Tags

CCSS.HSS.IC.A.1

If 50 crabs were captured and marked and then released and then a few days later 25 were caught and of those 5 were marked. What would the estimate of the population be?

• 500

• 250

• 75

• 200

Conservationists want to find the population of a species of mountain goat. On one day they capture 12 goats, tag them and release. A week later they capture 8 goats, 5 of which are tagged. What would the estimate of the population be?

• 19

• 40

• 72

• 30

I have a box with 300 balls in. I take 100 balls and mark them, put them back in and mix them up...If I took a sample of 60 balls...how many would i expect to be marked?

• 150

• 75

• 50

• 20

Tags

CCSS.6.RP.A.3B

What is this method called?

• Sampling

• Mark-Release

• Capture-Recapture

• Random sampling

A farmer wants to estimate the number of rabbits on his farm.

On Monday he catches 120 rabbits.

He puts a tag on each rabbit.

He then lets the rabbits run away.

On Tuesday the farmer catches 70 rabbits.

15 of these rabbits have a tag on them.

Work out an estimate for the total number of rabbits on the farm.

• 560

• 500

• 120

• 1000

There are N beads in a jar.

40 of these beads are black.

Julie takes at random a sample of 50 beads from the jar.

5 of the beads in her sample are black.

Work out an estimate for the value of N.

• 120

• 200

• 450

• 400

Tags

CCSS.7.RP.A.3

Clive wants to estimate the number of bees in a beehive.

Clive catches 50 bees from the beehive.

He marks each bee with a dye.

He then lets the bees go.

The next day, Clive catches 40 bees from the beehive.

8 of these bees have been marked with the dye.

(i) Work out an estimate for the number of bees in the beehive.

• 350

• 250

• 220

• 400