Answer:
4.8%
Explanation:
to do this create a ratio and cross-multiply

now that we have a our ratio, where x = the percent of poisonous trees, we can cross-multiply and solve to find its value
cross-multiplying leaves you with

now solve for x, dividing both sides of your equation by 1240
once you've divided, you should be left with

since this number is already out of 100, it is equivalent to your percent, so slap a percent sign on the end and you're done!