The work of a student to solve a set of equations is shown below: equation 1: m = 8 + 2n equation 2: 4m = 4 + 4n step 1: −4(m) = −4(8 + 2n) 4m = 4 + 4n step 2: −4m = −32 − 8n 4m = 4 + 4n step 3: −4m + 4m = −32 − 8n + 4n step 4: 0 = −32 − 4n step 5: n = − 8 in which step did the student first make an error? (4 points) a. step 1 b. step 2 c. step 3 d. step 4

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?