MATH 10041 Lecture Notes - Lecture 7: Scatter Plot

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

Document Summary

Chapter 4- regression analysis: exploring associations between variables. Scatterplot- primary tool for examining two-variable relationships (only when both are numerical) Location of each point depends on the two variables. Weak- large amount of scatter (large spread) Strong- clear path of scatter (small spread) Linear- tends to increase or decrease at the same rate. Explain what these all mean in context! The graph above has a moderately strong, linear negative trend. This means that the observations have some variety and decreases. Correlation coefficient- number that measures the strength of the linear association between two numerical variables. Makes sense only if the trend is linear and both variables are numerical. The closer to -/+ 1 it is, the stronger the association. The closer to 0 it is, the weaker the association r= positive -> positive trend r= negative -> negative trend. Find r on calculator- stat-edit-enter data (l1 & l2)-stat-calc-4:linreg(ax+b)-