At a middle school science fair, all the science fair projects used mathematics, but only 40% of the projects display the mean or the median. 37% of all the science fair projects display the mean and 22% of all the science fair projects display the median.

1. Apply the addition rule, P(mean or median) = P(mean) + P(median) - P(mean or median) , to find the probability that a randomly selected project at this science fair displays the mean and the median.

P(mean and median) =
​