Okay, the number above the sigma(4) indicates what value you go to, and what's below the sigma tells you where to start, and the stuff on the right is the expression you're using.
So we start with 1 and go to 4, adding all the values in between.
(2(1))^2 + (2(2))^2 + (2(3))^2 + (2(4))^2
2^2 + 4^2 + 6^2 + 8^2
4 + 16 + 36 + 64
120
Answer:
35%
Step-by-step explanation:
easy way to remember: 
= 
= 35%
Answer:
(a) fave = 8
(b) c = 64/9
(c) c ≈ 7.111
Step-by-step explanation:
(a) The average value of the function is its integral over the interval, divided by the width of the interval.

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(b) We want ...
f(c) = 8
3√c = 8 . . . . . use f(c)
√c = 8/3 . . . . . divide by 3
c = (8/3)² . . . . square
c = 64/9
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(c) c ≈ 7.111