Question

You are studying a population of ducks. There are 10 ducks in the population and you are studying how much they weigh in pounds. In this population there are 5 ducks that weigh 5 pounds, and 5 ducks that weigh 4 pounds. You take a sample of 4 ducks of the following weights: 4,4,4,5. If you calculate the sample mean weight of these four ducks, what would be your sampling error?

Answer 1

Sampling error is the difference between the value of sample mean and population mean.

Sample mean

$= \frac{4+4+4+5}{4}$

sample mean = 4. 25

Population mean

$= \frac{5+5+5+5+5+4+4+4+4+4}{10}$

population mean = 4.5

Sampling error = population mean - sample mean

= 4.5 - 4.25

= 0.25