A sapling is a young tree. Suppose ten four year old oak saplings are randomly sampled in the Sierra Nevada foothills. The heights (in feet) are given below. Calculate the mean height of the sample. Round your answer to two decimal places, as needed. 4.2, 8.1, 5.5, 5.0, 3.8. 6.3, 6.7. 4.5, 6.0, 5.9