All you need to do is add te averages together then divide them by 2.
91%+78%=169%
169%÷2=84.5%
So the new test average is 84.5%
Cheyenne sells 7.1428% of her cards at the craft fair. I hope this helps you!
Range: lowest number subtracted from highest number
105.40 - 27.50 = $77.90
Check out the attached image. It's essentially the same as the given figure but I've added on x and y.
Given:
AB = 5
BC = 10
CD = 2
AE = 8
Unknowns:
EF = x
FG = y
The goal is to find the values for x and y. Once we know them we can find the length of AG
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Let's find x first.
AB/BC = AE/EF
5/10 = 8/x
5x = 10*8 <<--- cross multiply
5x = 80
5x/5 = 80/5
x = 16
Or more simply: EF is twice as long as AE since BC is two times longer than AB
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Now use that x value to find y
AC/CD = FA/FG
(AB+BC)/CD = (AE+EF)/FG
(5+10)/2 = (8+x)/y
15/2 = (8+x)/y
15/2 = (8+16)/y <<--- plugged in x = 16
15/2 = 24/y
15y = 2*24 <<--- cross multiply
15y = 48
15y/15 = 48/15
y = 48/15
y = 16/5
y = 3.2
Therefore, AG is...
AG = AE+EF+FG
AG = 8+x+y
AG = 8+16+3.2
AG = 24+3.2
AG = 27.2
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Answer: choice C) 27.2