# statistics

Correlation and Regression”

View the 2014 SAT Scores by State: http://www.commonwealthfoundation.org/policyblog/detail/sat-scores-by-state-2014

Using Microsoft Excel, draw a scatterplot of the Participation Rate (x-axis) vs. Combined SAT Scores (y-axis). DO NOT USE THE %-SYMBOLS when putting the data into the spreadsheet. ALSO, DO NOT change the percents to decimals. For example, North Dakota has a participation rate of 2.3% and a combined SAT score of 1816. In the Excel spreadsheet, you would simply input 2.3 & 1816 for the North Dakota data. Provide a copy of your scatterplot in the discussion thread.

Once you draw the scatterplot, describe the relationship between participation rate and combined SAT scores. Make sure you state whether it is a positive or negative relationship and whether the relationship is strong, moderate, or weak. Also, what does this relationship say in “simple language?”

Find the value of the correlation coefficient (r) and explain what that means in relationship to the problem.

Find the equation of the least squares regression line.

Use the equation of the least squares regression line to “predict” the combined SAT score for a state whose participation rate is 21.8%. Does “correlation imply causation?” Use the example of SAT scores and participation rate to discuss this with your classmates.