10. A system of equations is shown below. 4x + y = 8
2x - 3y = 18
If the first equation is multiplied by a constant and the result is added
to the second equation, which equation could result?
-2y = 26
7y = 44
-10x = -6
14x = 42

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?