To win a contest the number of beans in a jar has to be guessed within 20 of the actual number. If the number of beans in the jar is 645 which equation can be used to find the minimum and maximum number of beans that will win the contest what is the maximum guess that could win.

The number of chocolate chips in an 18-ounce bag of chocolate chip cookies is approximately normally distributed with a mean of 1252 chips and standard deviation 129 chips. (a) what is the probability that a randomly selected bag contains between 1100 and 1500 chocolate chips, inclusive? (b) what is the probability that a randomly selected bag contains fewer than 1125 chocolate chips? (c) what proportion of bags contains more than 1225 chocolate chips? (d) what is the percentile rank of a bag that contains 1425 chocolate chips?