Scatterplots Question 3

A scatterplot of student height, in inches, versus corresponding arm span length, in inches, is shown below. One of the points in the graph is labeled $A$ .

If the point labeled A is removed, which of the following statements would be true?

The slope of the least squares regression line is unchanged and the correlation coefficient increases.

The slope of the least squares regression line is unchanged and the correlation coefficient decreases.

The slope of the least squares regression line increases and the correlation coefficient increases.

The slope of the least squares regression line increases and the correlation coefficient decreases.

Approach

The scatterplot shows a linear positive trend. The $A$ datapoint is an outlier. Removing it will result in a much better fit of the data, corresponding to a increase in the correlation coefficient. The slope will increase since the $A$ value is below the line of best fit. Removing it will make the line steeper.