Mariano determined that the more he practiced piano the less mistakes he would make. he found that for each hour ne
practiced each week he could decrease his mistakes by 30%. mariano computed a best-fit equation of y=-0.3x + 17
where y is the total mistakes and x is the number of hours practiced. use mariano's equation to estimate the number of
mistakes per page made by a student who has practiced for 21 hours. round to the nearest tenth if necessary.