We can check by subbing in the values.
7x + 2y = -7
(7,9).....x = 7 and y = 9
now we sub
7(7) + 2(9) = -7
49 + 18 = -7
67 = -7 (incorrect)....therefore, (7,9) is NOT a solution for this equation
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:
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%.
(13 + x)/(50 - x ) = (2/1)
Cross Multiply
2(50-x) = 1(13 + x)
100 - 2x = 13 + x
add 2x to both sides
100 -2x + 2x = 13 + x + 2x
100 = 13 + 3x
Subtract 13 from both sides
100 - 13 = 13 - 13 + 3x
87 = 3x
divide both sides by 3
29 = x
(13 + 29)/(50-29) = 42/21 = 2 to 1 ratio
(4/5)*what = (2/3)
Multiply by 5/4
.. what = (2/3)*(5/4)
.. what = 5/6