1. At a middle school science fair, all the science fair projects used mathematics, but only 30% of the
projects display the mean or the median. 27% of all the science fair projects display the mean and
16% of all the science fair projects display the median.
a. Apply the addition rule,
b. P(mean or median) = P(mean) + P(median)-P(mean and median), to find the
probability that a randomly selected project at this science fair displays the mean and the median.
Explain or show your reasoning.