Suppose certain coins have weights that are normally distributed with a mean of 5.663 g and a standard deviation of 0.066 g . A vending machine is configured to accept those coins with weights between 5.553 g and 5.773 g. a. If 280 different coins are inserted into the vending machine, what is the expected number of rejected coins? The expected number of rejected coins is nothing . (Round to the nearest integer.) b. If 280 different coins are inserted into the vending machine, what is the probability that the mean falls between the limits of 5.553 g and 5.773 g? The probability is approximately nothing . (Round to four decimal places as needed.)