These data describe housing prices in the Philadelphia area. Each of the 110 rows of this data table describes a region of the metropolitan area. (Several make up the city of Philadelphia.) One column, labeled Selling Price, gives the median price for homes sold in that area during 1999 in thousands of dollars. Another, labeled Crime Rate, gives the number of crimes committed in that area, per 100,000 residents.
(a) Make a scatterplot of the selling price on the crime rate. Which observation stands out from the others? Is this outlier unusual in terms of either marginal distribution?
(b) Find the correlation using all of the data as shown in the prior scatterplot.
(c) Exclude the distinct outlier and redraw the scat-terplot focused on the rest of the data. Does your impression of the relationship between the crime rate and selling price change?
(d) Compute the correlation without the outlier. Does it change much?
(e) Can we conclude from the correlation that crimes in the Philadelphia area cause a rise or fall in the value of real estate?