Question

population size sampling

quiz answer!!

Consider the following scenario: Imagine that you are a wildlife biologist assessing a population of penguins on an isolated island (meaning there are no nearby landmasses of penguins). On your first day out, you capture 20 penguins, tag them, and release them back on the island. After a week, you return to the island, catch 55 penguins, and find that 11 of them are marked with tags Calculate the total population size (N). N- Is the total population estimate reliable (given the rule of thumb)? 1. Not very reliable 2. Reliable This sample is (1 or 2)

Answer 1

A population is made up of all the organisms of one species living mutually in one place at the same time. All of the people living together in one town are considered a population. All of the penguins living in a place are a population. Scientists keep follow the change (increase or decrease) of population numbers to make decisions about issues that affect that population.

It is often not realistic or even promising to count all the members of a population. A population can be so large that counting it would be like trying to count the number of grains of sand on a beach. To resolve these counting problems, scientists take data from just a small portion of the population called a sample. They take several samples and then use the average size of those samples to estimate the entire population size.

Here,

On the first day we capture 20 penguins.

So, the first sample size is = 20

On the second sampling we capture 55 penguins, but 11 of them are form previous sample.

So, the actual second sample size = 55-11

                                                      = 44

Then, the population size (N) = (First sample size + Second sample size)/2

                                               = (44+20)/2

                                              = 32

The total population estimate is not very reliable, because here the number of sampling is very less. In these type of case if number of sampling is more the actual population size is more accurate.