step 1: bobby: first you multiply 1.12 by $2.50, and you get $2.80. $2.80 is how much bobby spent.
step 2: carla: you have to do 1.4 times $2.20, and you'll get $3.08.
therefore, carla spent more money
2) it does because it multiplies each number by 3
3) it is appropriate because it is linear there is a correlation
these are the answers for 2 and 3