The weight of corn chips dispensed into a 10-ounce bag by the dispensing machine has been identified as possessing a normal distribution with a mean of 10.5 ounces and a standard deviation of 2 ounces. Suppose your job is to calculate the mean of 100 randomly selected bags of chips from this dispensing machine. If you repeat your job many times, you will get many values of sample mean. What percentage of all sample means will fall between 10.20 and 10.50 ounces?