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%.
Step-by-step explanation:
in such a case the easiest approach might be using the point-slope form of a line equation :
y - y1 = m(x - x1)
with m being the slope, and (x1, y1) being a point on the line.
so, in our case that would be
y - 8 = 8(x - 4)
simplified this would be
y - 8 = 8x - 32
y = 8x - 24
FYI - this would be then the slope-intercept form (-24 would be the intercept point on the y-axis).
Answer:
5.5
Step-by-step explanation:
The y-intercept of the line graph shown above is the value of the point where the line cuts the y-axis. The y-intercept of this graph is between 5 and 6. However, we can get an accurate value by calculation. This can be done by generating an equation of the line.
Recall the slope-intercept equation, 
, where m = slope of the line, b = y-intercept.
To generate the equation of the line, first find slope using the points (-2, 7) and (6, 1):
.
Substitute m = ¾ and the coordinates (6, 1) into the slope-intercept equation to find the y-intercept (b):
Therefore, b = y-intercept = 5.5.
To generate the equation of the line, plug in the values of m and b, we would have:
y = ¾x + 5.5
The y-intercept of the line of the graph is 5.5.
Answer:
if you becomes a.. what is this mean
<u>Step 1</u>
Convert mixed fractions into fractions
6 2/5 = (6*5)+2) / 5 = 32/5
2 2/3 = (2*3)+2) / 3 = 8/3
<u>Step 2</u>
32/5 ÷ 8 / 3 ; where 32/5 is the 1st fraction and 8/3 is the 2nd fraction
<u>Step 2 (A)</u>
Get the reciprocal of the 2nd fraction:
From 8/3 to 3/8
<u>Step 2 (B)</u>
Multiply 1st fraction to the reciprocal of the 2nd fraction
32/5 * 3/8 = (32*3) / (5*8) = 96/40
<u>Step 2 (C)</u>
Simplify the fraction
96/40 divide by 4 will become 24/10
24/10 divide 2 will become 12/5. The simplest fraction of 96/40
The unit rate is 12/5 = 2 2/5 revolutions per second
