Can someone help w Q21? pls no links, i’m really confused

Use the inverse of the function y=x^2-18x to find the unknown value [tex]y = \sqrt{bx + c \: + d} [/tex]

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?

Which graph represents the equation y =4x