A new Italian espresso machine at a local restaurant is regulated so that the amount of espresso dispensed is approximately normally distributed with a mean of 1.5 ounces and a standard deviation of 0.15 ounces. The machine is checked periodically by taking a sample of 9 ice cream cups and computing the average content. If falls in the interval , the machine is thought to be operating satisfactorily; otherwise, we conclude that ounces. Find the probability of committing a type I error when ounces.