1. The problem asks for the fraction of trees that are pear trees out of the total number of trees. 2. First, find the total number of trees by adding the pear trees and bay trees: $$4 + 22 = 26$$ 3. The fraction of pear trees is the number of pear trees over the total number of trees: $$\frac{4}{26}$$ 4. Simplify the fraction by dividing numerator and denominator by their greatest common divisor, which is 2: $$\frac{4 \div 2}{26 \div 2} = \frac{2}{13}$$ 5. Therefore, the fraction of trees that are pear trees in simplest form is: $$\frac{2}{13}$$