Suppose that the consumer price index (cpi), which meansures the cost of a typical package of consumers goods, stood at 140.7 in 1990 and 190.7 in 2000. let x=0 correspond to 1990, and establish the cpi in 1998 and 2004. which linear equation best models the cpi? a) y=-5x+140.7b) y=5x-140.7c)y=5x+140.7in 1998, the cpi would be in 2003, the cpi would be