The local Toyota dealership pays an average of $9,260 with a standard deviation of $1099 for used car trade-ins. They sell new c
ars at an average of $28,451 with a standard deviation of $3392. Assume independence of new car and trade-ins. What are the mean and standard
deviation of the revenue this dealership should expect when a person trades in a car and purchases a new one?
You can make an cb chart. so to equal -6 you need the numbers -7, 1. so now the equation is ( x - 7 )( x + 1 ). if you want to solve it set it equal to 0 and solve.