A biologist studies elephants. She records the weights of 500 newborn elephants in a table. What is the best way for the biologist to estimate the population mean of the newborn elephants’ weights?

Calculate the mean of the first 50 weights in the table.
Calculate the mean of the first 50 weights in the table.

Calculate the mean of the first 5 weights in the table.
Calculate the mean of the first 5 weights in the table.

Calculate the mean of 50 randomly selected weights in the table.
Calculate the mean of 50 randomly selected weights in the table.

Calculate the mean of 5 randomly selected weights in the table.

1 answer

To estimate the population mean of the newborn elephants’ weights effectively, the best approach would be to:

Calculate the mean of 50 randomly selected weights in the table.

This method is preferred because:

  1. Random Selection: By randomly selecting weights, you reduce bias and increase the likelihood that your sample accurately reflects the population. This helps account for variability in the data.

  2. Sample Size: A sample size of 50 is large enough to provide a reasonable estimate of the population mean, while still being manageable.

Calculating the mean of just the first 5 or even the first 50 weights may not adequately represent the overall population, especially if those weights are influenced by specific factors (such as environmental conditions or the genetic backgrounds of the first few recorded individuals).

Thus, the best choice is to calculate the mean of 50 randomly selected weights.