What one is non Nonlinear

Monthly water bills for a city have a mean of $108.43 and a standard deviation of $32.09. find the probability that a randomly selected bill will have an amount greater than $155, which the city believes might indicate that someone is wasting water. would a bill that size be considered unusual?

What number line represents the solution set for the inequality -1/2 greater than or equal to 4

(-y to the power of 2 - 4y- to the power of 2 -6 y +3)