In the mass production of a certain mechanical part, the average length of the part is 10.500 inches. The lengths of many parts follow a normal distribution. The standard deviation of the lengths is 0.007 inches. If 1000 parts are made, how many parts have lengths of less than 10.510 inches? If the length of the part must be between 10.485 inches and 10.515 inches to be acceptable, how many parts are acceptable?