In which situation can a constant of proportionality be identified A. Allison earns $8 per hour for h hours and an $8 bonus for each cell phone plans she sells. B. Ben buys x cans of dog food for $1.25 each and uses a coupon $7 off his entire purchase. C. Claire orders b books online for $4.50 each plus shipping charges $0.30 for each book. D. John runs 3 miles per day for m days in a week and bicyles 20 miles/day the remaining days in the week.
C is the only situation in which there is a clear constant of proportionality and no offset (no initial value). Claires rate is ($4.50 + $0.30)/book, or $4.80/book.