The answer is $48.60 you just have to multiply the amount of bags times the cost of each bag to get your amount so
15 x 3.24 =48.60
Let
be the weight of i-th player.
1. If the mean weight of 4 backfield members on the football team is 221 lb, then

2. If the mean weight of the 7 other players is 202 lb, then

3. From the previous statements you have that

Add these two equalities and then divide by 11:

Answer: the mean weight of the 11-person team is 