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 
V=4/3πr^3, so substitute what you know. Input the volume so you only have to solve one variable, the r, radius.
Answer:
Answer is m∠4=40
Step-by-step explanation:
take note that m∠6 & m∠7 are vertical angles. Vertical angles are equal to each other, therefore m∠6 is equal to m∠7.
m∠6 = m∠7 (vertical angles)
11x + 8 = 12x – 4
12x - 11x = 8 + 4
x = 12
so
m∠6 = 11x + 8
m∠6 = 11(12) + 8
m∠6 = 132 + 8
m∠6 = 140
m∠4 = 180 - m<6
m∠4 = 180 - 140
m∠4 = 40
