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 
The answers to the questions
Answer:
x = 6
Step-by-step explanation:
All triangle angles add up to 180 so:
90 + 5x + 6 + 54 = 180
5x + 150 = 180
5x = 30
x = 6
One way of calculating the volume would be to convert all of these measurements to decimal:
V = (18 in)(30 in)(8 in) = 4320 cubic in
The original expression evaluates to 54.4 as shown in the first working.
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For some reason, 3.4 got transcribed to be 1.7 in the 3rd line of the second working. There is no math operation in the expression that requires 3.4 to be divided by 2.
