PSYC 218 Lecture Notes - Lecture 12: Scatter Plot
Document Summary
So far: we have focused on single distributions. Now: focus on whether scores in one distribution are related to scores in another. Can be described by a straight line. Scatter plot of this: graph of paired values of x and y variables. Relationship between # of cars sold (x) and bonus salary (y) can be described in a straight line: A = y intercept (value of y when x = 0) First, you find the y intercept (a) Value of y where the line intersects the y axis . B = slope = y/ x = y2-y1 / x2-x1. Equation describes the relationship between y and x. If you increase x (# cars sold) by 1, then y (bonus salary) increases by 150. If relationship holds for other sales people. Equation lets us compute an appropriate value for y given any value for ex. When we use the equation for prediction. Y1 = predicted value of y variable.
