Electric companies trim trees growing near their lines to avoid power failures due to falling limbs. Applying a compound to slow the growth of the trees is less costly than trimming, but the compound kills some of the trees. Suppose that one such compound would kill 25% of oak trees. The power company tests the compound on 200 oak trees. Consider these an SRS from the population of all oak trees. What is the mean of the proportion of trees that are killed in samples of 200 trees?

What is the standard deviation of the proportion of trees that are killed in samples of 200 trees? Round your answer to the nearest thousandth.

Calculate probability that at least 27% of the trees in the sample are killed. Round to the nearest thousandth and leave your answer as decimal.