The chocolate factory "charlie’s own" produces limited-time boxes with exactly 9 chocolates. the research department of the factory models the weight of a chocolate by the random variable x, with expected value e(x) = 5 and variance var(x) = 0.09. customers who buy a box with chocolate weight less than 42.75 are reimbursed and given a coupon for their next purchase. give an estimate of the percentage of boxes with weight less than 42.75. leave your answer in terms of φ, the distribution function of a standard normal random variable.