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AP®︎/College Statistics

Course: AP®︎/College Statistics>Unit 5

Lesson 3: Residuals

Introduction to residuals and least-squares regression

In linear regression, a residual is the difference between the actual value and the value predicted by the model (y-ŷ) for any given point. A least-squares regression model minimizes the sum of the squared residuals.

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• WHERE does the -140 +14/3x come from??
• where did -140 come from?
• That's the point at which the regression line meets the y-axis, the y-intercept.
(1 vote)
• my question is the same as the first 2 previous...Please explain
• where did you get for 140 for y
• If you extend the y-axis, the y-intercept (the point where the line first hits the y-axis) will be approximately -140. Also, the slope of the line is 14/3. So, if you transcribe the above into the equation of the line- y=mx+b, you get y=-140+14/3x
• Did Sal pre-calculate the equation? I can't ever do it that fast!
Why are mx and b switched in places?
• Linear equations can be written as y=a+bx. This is how I learned them growing up in another country. Start at a and then go up from there.
• I have the same question...how did he get -140+14/3x. If Sal calculated it before...it should be said. How am I to grasp and understand what to be done
• Where did the -140 and the 14/3 come from? Thank you. (time stamp: 2.27min)