Answer:
a) 
b) r =-0.932
The % of variation is given by the determination coefficient given by 
and on this case 
, so then the % of variation explained by the linear model is 86.87%.
Step-by-step explanation:
Assuming the following dataset:
Monthly Sales (Y) Interest Rate (X)
22 9.2
20 7.6
10 10.4
45 5.3
Part a
And we want a linear model on this way y=mx+b, where m represent the slope and b the intercept. In order to find the slope we have this formula:
Where:
With these we can find the sums:
And the slope would be:
Nowe we can find the means for x and y like this:
And we can find the intercept using this:
So the line would be given by:
Part b
For this case we need to calculate the correlation coefficient given by:
![r=\frac{n(\sum xy)-(\sum x)(\sum y)}{\sqrt{[n\sum x^2 -(\sum x)^2][n\sum y^2 -(\sum y)^2]}}](https://tex.z-dn.net/?f=r%3D%5Cfrac%7Bn%28%5Csum%20xy%29-%28%5Csum%20x%29%28%5Csum%20y%29%7D%7B%5Csqrt%7B%5Bn%5Csum%20x%5E2%20-%28%5Csum%20x%29%5E2%5D%5Bn%5Csum%20y%5E2%20-%28%5Csum%20y%29%5E2%5D%7D%7D)
![r=\frac{4(696.9)-(32.5)(97)}{\sqrt{[4(278.65) -(32.5)^2][4(3009) -(97)^2]}}=-0.937](https://tex.z-dn.net/?f=r%3D%5Cfrac%7B4%28696.9%29-%2832.5%29%2897%29%7D%7B%5Csqrt%7B%5B4%28278.65%29%20-%2832.5%29%5E2%5D%5B4%283009%29%20-%2897%29%5E2%5D%7D%7D%3D-0.937)
So then the correlation coefficient would be r =-0.932
The % of variation is given by the determination coefficient given by and on this case , so then the % of variation explained by the linear model is 86.87%.
Answer:
8x = 75 + 5x
where x = length of one brick
25cm
Step-by-step explanation:
Answer:
24
Step-by-step explanation:
Hey!
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They already give us the slope, so we can solve the y-intercept.
We can use (3, -2).
y = 8x + b
-2 = 8(3) + b
-2 = 24 + b
-2 - 24 = 24 + b - 24
-26 = b
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Hence, the answer is 
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Hope This Helped! Good Luck!
Answer:
R(7a, 0 )
Step-by-step explanation:
R is on the vertical line RQ so will have the same x- coordinate as Q
R is on the horizontal line OR so will have the same y- coordinate as O
Thus coordinates of R = (7a, 0 )
