Population Math Practice

You are sampling pillbugs in the field. On your first day out, you capture and mark 50 pillbugs. A week later, you take a second sample and capture 55 pillbugs. Of those 55, 10 of them were marked. What is the estimate of your population size?

Show your work by uploading an image.

Mathematical Equivalence

ON

Tags

NGSS.MS-LS2-1

You are working for DCNR and are tracking deer populations at Erie Bluffs State Park. During your first week out, you tagged 15 deer. A month later, you took observations of deer and spotted 10. Of those 10, 5 were tagged. What is the estimated population of deer at Erie Bluffs?

Show your work by uploading an image.

Mathematical Equivalence

ON

Tags

NGSS.MS-LS2-1

NGSS.MS-LS2-4

You set up a 5 by 5 grid like the one pictured in this question. You counted the number of birch trees in 5 of the segments and got the following results:

Grid 1: 3 trees

Grid 2: 5 trees

Grid 3: 8 trees

Grid 4: 1 tree

Grid 5: 3 trees

Based on your survey, what is the estimated number of birch trees for the entire area?

Mathematical Equivalence

ON

Tags

NGSS.MS-LS2-1

Estimate this population size using random sampling.

Hint: You should sample 4 grid segments.

Show your work by uploading an image.

Answer explanation

You should count the number of dots in 4 of the segments. Then, you should add all those up and divide by 4 to find the average number of dots per grid segment. Finally, you should multiply that number by 16, since that is the total number of grid segments. Everyone's estimates will be slightly different based on what 4 segments you randomly picked to count.

Why did we use the paper slip method when sampling the grids?

• To ensure that all grids are sampled equally.
• To increase the accuracy of the sampling process.
• To save time and resources during the sampling process.
• To ensure random selection and avoid bias in the sampling process.

You took an initial population sample of 15 squirrels, which you tagged. Two weeks later, you took another sample of 10 squirrels. None were recaptured. Can you estimate the population size?

• Yes, the population size can be estimated with the information given.

• No, the population size cannot be estimated without recapturing any tagged squirrels.
• Yes, the population size can be estimated by assuming a certain capture rate.
• No, it is not possible to estimate the population size because the sample sizes were not large enough.