A well-known maker of jams and jellies packages its jams in jars labeled "250 milliliters." The process used to fill the jars is known to dispense an amount of jam
that is a Normally distributed variable with  = 252 milliliters and  = 0.9 milliliters.
If changing  while keeping  the same were possible for this process, what should 
be set at so that the percentage of jars filled with less than 250 milliliters will be at
most 0.2%?