Crimson
01-03-2009, 03:43 PM
Y=mX+C
m = ‘Gradient’ and C = ‘Y intercept’
The gradient is how steep the line is. This could be read as how many bars go up as to one bar across, or visa versa. However, I want my results to be as reliable as possible and to do this there is necessary equation. This equation gives the exact gradient of the line:
Change in Y/Change in X
To do this, you have to pick out two clear points on the line of best fit and find the change of the X value and the Y value.
As you can see, the change in the Y value is that of;
9000 – 8000 = 1000
And the change in the X value is that of;
48000 – 40000 = 8000
The next stage is to put these values into the equation and finish the sum.
1000/8000 = 1/8 = 0.125
Thus;
m = 0.125
~~~~~~~~~
Okay, so I have this so far for a small piece in my coursework. However, on my graph.. The line of best fit is negative so there should be a minus in my equation so it should be;
Y=-mX+C
But it's not. lol :D
I think I've done all the sums correctly but I was talking to a friend about it and he's not sure either. Is the sum correct, and I just need to put a minus in there and simply say,
"As the gradient is negative, a minus is needed." Or is my sum incorrect and is that the reason for the minus not being there?
There are also pictures and stuff in the word document but I can copy and paste them, so when it says "As you can see" you can actually see on the word document :P
Maaaaaaany thanks :)
m = ‘Gradient’ and C = ‘Y intercept’
The gradient is how steep the line is. This could be read as how many bars go up as to one bar across, or visa versa. However, I want my results to be as reliable as possible and to do this there is necessary equation. This equation gives the exact gradient of the line:
Change in Y/Change in X
To do this, you have to pick out two clear points on the line of best fit and find the change of the X value and the Y value.
As you can see, the change in the Y value is that of;
9000 – 8000 = 1000
And the change in the X value is that of;
48000 – 40000 = 8000
The next stage is to put these values into the equation and finish the sum.
1000/8000 = 1/8 = 0.125
Thus;
m = 0.125
~~~~~~~~~
Okay, so I have this so far for a small piece in my coursework. However, on my graph.. The line of best fit is negative so there should be a minus in my equation so it should be;
Y=-mX+C
But it's not. lol :D
I think I've done all the sums correctly but I was talking to a friend about it and he's not sure either. Is the sum correct, and I just need to put a minus in there and simply say,
"As the gradient is negative, a minus is needed." Or is my sum incorrect and is that the reason for the minus not being there?
There are also pictures and stuff in the word document but I can copy and paste them, so when it says "As you can see" you can actually see on the word document :P
Maaaaaaany thanks :)