2. At the grocery store checkout, you watch at the register as it rings up your purchases and coupons. The prices are as follows: $2.35 $1.17 $6.31 $1.75 $3.15 $8.79 $1.59 − $0.50 (coupon) − $1.00 (coupon) The register gives your total bill as $23.61 (a) Round each price and coupon to the nearest dollar and then estimate the total amount of the bill. (b) Using your estimate, determine whether the total on the register is reasonable. Justify your answer.