This activity involves investigating whether a difference really seems to exist between two sample means.

• 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.

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.