1.) The scores on a college placement test are normally distributed with mean 500 and standard deviation 65. a.) What percentage of people taking this exam will have scores higher than 390? b.) What percentage of the people taking this test will have scores between 450 and 485? c.) What percentage of the people taking this test will have scores between 425 and 530? 2.) The diameter of nails produced in a factory are normally distributed with a mean of 0.30 inches and a standard deviation of 0.01. What percentage of nails will have a diameter greater than 0.32 inches? 3.) The amount of tip the waiters in an exclusive restaurant receive per shift is normally distributed with a mean of $70-and a standard deviation of $8. A waiter feels he has provided poor service if his total tip for the shift is less than $55. Based on his theory, what is the probability that he has provided poor service