The amount of fill (weight of contents) put into a glass jar of spaghetti sauce is normally distributed with mean = 857 grams and standard deviation of = 13 grams. (a) Find the probability that one jar selected at random contains between 845 and 858 grams. (b) Find the mean of the x distribution. (ii) Find the standard error of the x distribution. (e) Find the probability that a random sample of 29 jars has a mean weight between 845 and 858 grams. Solution mean=857, s=13 a. P(845.