The life of light bulbs is distributed normally. The variance of the lifetime is 625 and the mean lifetime of a bulb is 530 hours. Find the probability of a bulb lasting for at most 564 hours. Round your answer to four decimal places.

You're locked out of your house. the only open window is on the second floor, 25 feet above the ground. there are bushes along the edge of the house, so you will need to place the ladder 10 feet from the house. what length ladder do you need to reach the window?