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%.
Answer:
13A. 14, 48, 50
13B. both mulitpled by 2?
13C. 56, 125
14. Yes
Step-by-step explanation:
The expression for the polynomial graphed will be y(x) = (x + 3)(x - 1 )(x - 4 ).
<h3>How to factor the polynomial?</h3>
From the graph, the zeros of the polynomial of given graph are:
x = -3
x = 1
x = 4
Equate the above equations to zero
x + 3 = 0
x - 1 = 0
x - 4 = 0
Multiply the equations
(x + 3)(x - 1 )(x - 4 ) = 0
Express as a function gives;
y = (x + 3)(x - 1 )(x - 4 )
Hence, the factored form of the polynomial will be y = (x + 3)(x - 1 )(x - 4 ) .
Read more about polynomials at:
brainly.com/question/4142886
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hope this helped!!
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