Question

SOLVE Suppose you are helping scientists conduct a study of a population of Clear Lake
hitch, which is a fish species that lives in Californian lakes. The scientists initially capture
80 hitch from a lake and tag all of them. After 30 days, they capture 100 hitch and count
20 tags. Use the space below to calculate the estimated number of hitch in the lake. Show
your work

Answer 1

Answer:

400

Explanation:

Scientists tagged 80 hitch. When they capture 100 hitch, 20 are tagged. In order to estimate the population of hitch, we can assume that this proportion is consistent.

This means for every 20 tagged hitch, there are 80 untagged. We know there are 80 tagged total, so we need to multiply 20 by 4 to get it to 80. To keep the proportion equal we also need to multiply the untagged hitch.

$\frac{20}{80}$ * $\frac{4}{4}$ = $\frac{80}{320}$

Still following the proportion, we have 80 tagged hitch and 320 untagged hitch. 80 + 320 = 400 hitch total.