Rodney is purchasing new window blinds for his home. Lowe's charges $6 per window blind and an additional $50 as an installation fee. Home Depot charges $9 per window blind with an additional $25 as an installation fee. Part 1: Which store would charge less for installing 7 window blinds? Justify your answer. Part 2: How much money is saved by using Home Depot instead of Lowe's to install 4 window blinds?