Statistics: Difference in Means

Objectives

• Students will use a simulated sampling distribution to estimate the probability of an outcome.
• Students will find and interpret an estimated probability that the difference between two means is greater than or equal to an observed difference.

About the Lesson

This activity involves investigating whether a difference really seems to exist between two sample means.
This activity will give students the following opportunities:

• Generate an observed difference for the lifetime of two kinds of compact fluorescent light bulbs (the context could easily be changed).
• Check that the assumptions concerning the samples are met (large population relative to the sample, independence, differences are normally distributed).
• Generate a simulated sampling distribution for the difference of the means.
• Compare the observed difference to the simulated sampling distribution to decide how likely it would be to see a difference as large or greater than the observed difference.