Andre received $60 for his birthday that he put in his piggy bank. each week, he puts 3 more dollars in his bank so that the amount of money in dollars d in his bank is given by d = 3w + 60 where w is the number of weeks. his sister lana him find how much money he will have after 4, 15, 20, and 36 weeks. the table below shows her results. find the rate of change using lana’s values for d and w. explain whether this is a linear model.