Donald Duck wants to construct a sample mean chart for controlling the service life of Scrooge McDuck's vault door security to ensure the protection of his Number One Dime. He knows from numerous previous samples that this service life is normally distributed with a mean of 500 hours and a standard deviation of 20 hours. On three recent production batches, he tested service life on random samples of four security panels, with these results: Sample 495 Service Life (hours) 500 525 460 470 470 If he uses upper and lower control limits of 520 and 480 hours, on what sample(s) (if any) does service life appear to be out of control? O both samples 2 and 3 O sample 3 O sample 2 sample 1