Una was asked to write about predicting population means by taking the means of samples. She recorded a list of some statements generated from her classmates.

Which statements are true? Select three choices.
The best prediction of the population mean is the value that falls between the least and greatest sample means.
It is unlikely that the population mean will be the least or greatest mean from the samples.
If the means of different samples are close in number, or have small variation, then they cannot be used to make predictions for the actual population.
A more accurate prediction of the population mean can be made by decreasing the number of random samples.
To find the range of the sample means, subtract the least value from the greatest value.

1 answer

Let's analyze the statements one by one to determine which ones are true:

  1. The best prediction of the population mean is the value that falls between the least and greatest sample means.

    • False. The best prediction of the population mean is generally the mean of the sample means, rather than just a value between the least and greatest sample means.
  2. It is unlikely that the population mean will be the least or greatest mean from the samples.

    • True. The population mean is more likely to fall within the range of the sample means rather than being the extreme values (least or greatest).
  3. If the means of different samples are close in number, or have small variation, then they cannot be used to make predictions for the actual population.

    • False. If the means of different samples are close in number and have small variation, it actually indicates that these sample means provide a reliable estimate for the population mean.
  4. A more accurate prediction of the population mean can be made by decreasing the number of random samples.

    • False. Generally, increasing the number of random samples improves the accuracy of the prediction for the population mean due to the reduction of sampling error.
  5. To find the range of the sample means, subtract the least value from the greatest value.

    • True. This statement is accurate; the range is calculated as the difference between the maximum and minimum values.

Based on the analysis, the three true statements are:

  • It is unlikely that the population mean will be the least or greatest mean from the samples.
  • To find the range of the sample means, subtract the least value from the greatest value.