A customer sent in a $230 check to pay off an overdue bill but failed to pay the interest that accrued over the 45 days after th
1 answer:
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Answer:
a)
b) Figure attached
c)
Step-by-step explanation:
We assume that th data is this one:
x: 30, 30, 30, 50, 50, 50, 70,70, 70,90,90,90
y: 38, 43, 29, 32, 26, 33, 19, 27, 23, 14, 19, 21.
a) Find the least-squares line appropriate for this data.
For this case we need to calculate the slope with the following formula:
Where:
So we can find the sums like this:
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:
b) Plot the points and graph the line as a check on your calculations.
For this case we can use excel and we got the figure attached as the result.
c) Calculate S^2
In oder to calculate S^2 we need to calculate the MSE, or the mean square error. And is given by this formula:
The degred of freedom for the error are given by:
We can calculate:
And now we can calculate the sum of squares for the regression given by:
We have that SST= SSR+SSE, and then SSE=SST-SSR= 792-601.67=190.33[/tex]
So then :
Answer:
-1
Step-by-step explanation:
You can write it as...
Carry the 4x
Then use the quadratic formula to solve, since you want to find the negative solution, you don't need to find the positive solution, so we will have
Therefore our answer is -1