MATH 10041 Lecture Notes - Lecture 8: Scatter Plot, Standard Deviation, Extrapolation

• School: Kent State University
• Department: Mathematics
• Course: MATH 10041
• Professor: Rajeev Rajaram

Document Summary

Regression line- tool for making predictions about future observed values. Mean and standard deviation are used to summarize a sample distribution; regression line is used to summarize linear trends! Y=mx+b - equation for a straight line. Y=a+bx - statistical equation for a straight line. Variables on the horizontal (x) axis make predictions about variables on the vertical (y) axis. Regression line is a line of averages. When the trend is linear, the regression line connects the points that represent the mean value of y for each x. For linear trends, a slope of 0 means there is no association between x and y. Pitfalls to avoid when interpreting linear models. Don"t fit linear models to nonlinear associations. Regression models are only useful for linear associations. Always make a scatter plot before fitting a regression line in case the plot is not linear, then you cannot use a regression line.