The mean height of trees in the forest of Zambales is 42 ft and the standard deviation is 3 ft. Assuming that the distribution of these trees follows a normal distribution, find the maximum height (in...

The mean height of trees in the forest of Zambales is 42 ft and the standard deviation is 3 ft.  Assuming that the distribution of these trees follows a normal distribution, find the maximum height (in nearest thousandths) which falls in the lower 20%.