# Associations_between_variables_week_13 - Understanding...

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Understanding associations between variables ScatterplotScatterplot matrixPearson’s correlation coefficientTesting the strength of a linear correlation
The scatterplot consists of an ordered pair (x, y) of data points in a rectangular coordinate system, where x come from a different variable than yIt helps to understand the association between two variablesEXAMPLEThe following is the data of maximum concentrations of CO and O3 for 2000 in 15 cities in the U.S.Draw an scatterplot of CO vs. OCityCO (ppm)O3 (ppm)Atlanta4.10.023Boston3.40.029Chicago8.30.032Dallas3.50.014Denver2.10.016Detroit4.40.024Houston4.20.021Kansas city1.80.017Los Angeles9.50.044New York9.30.038Philadelphia5.10.028Pittsburg 2.40.025San Francisco1.70.02Los Angeles2.40.021Washington4.90.023SCATTERPLOT3
SCATTERPLOT EXAMPLEThe following is the data of maximum concentrations of CO and O3 for 2000 in 15 cities in the U.S.CityCO (ppm)O3 (ppm)Atlanta4.10.023Boston3.40.029Chicago8.30.032Dallas3.50.014Denver2.10.016Detroit4.40.024Houston4.20.021Kansas city1.80.017Los Angeles9.50.044New York9.30.038Philadelphia5.10.028Pittsburg 2.40.025San Francisco1.70.02Los Angeles2.40.021Washington4.90.0231234567891000.010.010.020.020.030.030.040.040.050.05COO3
If the scatterplot shows a roughly elliptical cloud (instead of a