Answer:
86%
Step-by-step explanation:
Let g represent the mean mark for the 10 girls in the class. Then the mean mark for the class was ...
10g +20(62%) = 30(70%)
g = 3(.7) -2(.62) . . . . . . . . . divide by 10 and subtract 2(.62)
g = .86 = 86%
The mean mark for girls was 86%.
_____
You can do this in your head if you consider it in terms of deviations from the mean. The second equation above can be rewritten and factored as ...
g = 70% +2(70% -62%)
That is, because there are 2 boys for every girl, the girl's score is above the mean by an amount that is 2 times the amount that the boy's score is below the mean. The boys' score is below by 8%, so the girls' score is above by 16%, so is 86%.
9514 1404 393
Answer:
(0, 2), (5, 5)
Step-by-step explanation:
The w-intercept is the constant in the equation, so you know immediately that (x, w) = (0, 2) is one point on your graph.
Since the value of x is being multiplied by 3/5, it is convenient to choose an x-value that is a multiple of 5. When x=5, we have ...
w(5) = (3/5)(5) +2 = 3+2 = 5
So, (x, w) = (5, 5) is another point on your graph.
Answer:
60
Step-by-step explanation:
180-120=60so the answer is a 60
-2(2b-3)
Multiply the bracket by -2
Whenever multiplying a -negative number with a -negative number= + positive number.
(-2)(2b)(-2)(-3)
-4b+6
Answer: -4b+6
Answer:
Step-by-step explanation:
If two chords intersect inside a circle, then
DE * BE =AE * CE
10*x = 8*6
10x = 48
x = 48/10
x = 4.8
