The actual amount of coffee (in grams) in a 230- gram jar filled by a certain machine is a random variable whose probability density is given by
Find the probabilities that a 230- gram jar filled by this machine will contain
(a) At most 228.65 grams of coffee;
(b) Anywhere from 229.34 to 231.66 grams of coffee;
(c) At least 229.85 grams of coffee.