Patty buys a new car and gets it appraised every few years. After owning the car for 3 years, it’s value is $15,000. After owning the car for 5 years, it’s value is $9,000. What is the constant of proportionality in this inverse variation?

An office supply company conducted a survey before marketing a new paper shredder designed for home use. in the survey, 80 % of the people who tried the shredder were satisfied with it. because of this high satisfaction rate, the company decided to market the new shredder. assume that 80 % of all people are satisfied with this shredder. during a certain month, 100 customers bought this shredder. find the probability that of these 100 customers, the number who are satisfied is 69 or fewer.