Y 10 150 37 5 a Is this linear or exponential Years since 1985 Number of Cell Phone users 2 9 375 Cinsar 0 200 4 1 50 c Find the equation of the function by using the appropriate sequence formula 498 3 2 3438 2 8 In 1985 there were 285 cell phone subscribers in the small town of Centerville The number c subscribers increased by 75 per year after 1985 Don t consider a fractional part of a perso b What is the common difference or ratio 3 d Find the appropriate regression equation by using the calculator Round to the nearest that 4 5 1527 872 6 8186 4677 2672 8 7 in 1997 14325 25069 a Determine an equation for a function that models this data set Round to the nearest b