a coffee machine is supposed to dispense 8 ounces (oz) of coffee into a paper cup. in reality, the amounts dispensed vary from cup to cup. however, if the machine is working properly, the standard deviation of the amounts dispensed should be less than 0.4 oz. to test this, a random sample of 15 cups was taken, and it give a standard deviation of 0.255 oz. at the 5% significance level, do the data provide sufficient evidence to conclude that the standard deviation of the amounts being dispensed is less than 0.4 oz? why is it important that the standard deviation of the amounts of coffee being dispensed not be too large?