Answer:
x+y/4 = 1/2
x-3y/3 = 2
move variables to one side:
multiply the first equation by 4 to get: x+y =2
and the second equation by 3 to get: x-3y =6
then subtract the equations to cancel out x:
x+y = 2
- x-3y = 6
then u get
y--3y = 2-6
4y = -4
y=-1
substitute to solve for x:
x-1 / 4 =1/2
x-1 = 2
x=3
check:
3+-1
2/4= 1/2
correct!!!
Answer:
II. The sum of the residuals is always 0.
Step-by-step explanation:
A least squares regression line is a standard technique in regression analysis used to make the vertical distance obtained from the data points running to the regression line to become very minimal or as small as possible.
For any least-squares regression line, the sum of the residuals is always zero.
Basically, residuals are used to measure or determine whether or not the line of regression is a good fit or match for the data by subtracting the difference between them i.e the predicted y value and the actual y value, for the x value respectively.
Hence, the statement about residuals which is true for the least-squares regression line is that the sum of the residuals is always zero (0).
Answers:
Horizontal Line: y = 5
Vertical Line: x = 8
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Explanation:
All horizontal lines are of the form y = k, for some constant k. We want the horizontal line to pass through (8,5), meaning every point on this horizontal line must have y coordinate 5. Therefore, y = 5 is the equation of the horizontal line. Two such points on this line are (1, 5) and (8, 5). All that matters is the y coordinate is 5. The x coordinate can be anything you want. The slope of any horizontal line is 0.
Flipping things around, all vertical lines will have the x coordinate of each point be the same value. Draw a vertical line through (8,5) and note how each point has x coordinate of 8. Two such points are (8,1) and (8,5). Therefore, the equation of the vertical line is x = 8. The y coordinate can be any value you want. The slope of any vertical line is undefined. Unlike the horizontal line, we cannot write this equation in slope intercept form (namely because the slope isn't defined).
The equation would be:
3.50 + 0.15x
x represents each 'late day'
