A Quality Analyst wants to construct a sample mean chart for controlling a packaging process. He knows from past experience that whenever this process is under control, package weight is normally distributed with a mean of twenty ounces and a standard deviation of two ounces. Each day last week, he randomly selected four packages and weighed each: If he uses upper and lower control limits of 22 and 18 ounces, on what day(s), if any, does this process appear to be out of control