STAT 100 Chapter 15: Chapter 15 STATS.docx

• School: Simon Fraser University
• Department: Statistics
• Course: STAT 100
• Professor: Derek Bingham

Document Summary

A regression line is a straight line that describes how a response variable y changes as an explanatory variable x changes. (predict the value of y for a given value of x) Because we want to predict y from x, we want a line that is close to the poitsn in the vertical direction. The least-squares regression line of y on x is the line that makes the sum of the squares of the vertical distances of the data points from the line as small as possible. X stands for the explanatory variable and y for the response variable. The number b is the slope of the line (the amount by which y changes when x increases by one unit) The number a is the intercept (the value of y when x = 0) To use the equation for prediction, just substitute your x-value into the equation and calculate the resulting y-value.