Data collected from the state of Florida includes:

y = crime rate = Annual number of crimes in county per 1000 population

x1 = education = Percentage of adults in county with at least a high school education

x2 = urbanization = Percentage in county living in an urban environment

Multivariate regression output from R is given below (note that the numbers are not the same as in the text book):



lm(formula = y ~ x1 + x2)


Min 1Q Median 3Q Max

-34.693 -15.742 -6.226 15.812 50.678


Estimate Std.Error t value Pr(>|t|)

(Intercept) 44.4727 19.4023 xxxxx xxxxx

x1 -0.4281 0.3937 xxxxx xxxxx

x2 0.5296 0.1398 xxxxx xxxxxx


Residual standard error: 17.30 on 64 degrees of freedom

Multiple R-squared: 0.5373 Adjusted R-squared: 0.4549

F-statistic: 29.21 on 2 and 64 DF, p-value: 1.19e-09

How many data points were used in fitting this multiple regression model?