This is about Multiple Linear Regression.

We are interested in the relationship between Risk of hospital-related infection in percent (Y) Length of a patient's stay in the hospital in days (Xl) Number of nurses during patient stay (X2) Region [NE, NC, S, WI where the patient was hospitalized (X:) The following regression suggests the intercept for the regression line between infection risk and number of nurses is different between region W and region NE. Coeffi ci ents : (Intercept) 1 ength_stay number_nurses regi onNC regi ons regl onw Si gnif. codes: Estimate -o .6835073 o .4869984 o .0017386 -0.2055650 -o .1846063 1.0968139 std. Error t value 0.6396241 o. 0631103 o .0006312 o. 2088366 0.2169073 0.2673605 -1.069 7.717 2.754 -o. 984 -o. 851 4.102 0.28657 6.14e-13 *** O .00644 o. 32618 o. 39577 6.01e-05 *** .001 0.01 0.05 0.1 ' 1 Residual standard error: 1.012 on 194 degrees of freedom Multiple R-squared: 0.4301, Adjusted R -squared: 0.4154 Fstatistic: 29.28 on 5 and 194 DF, pvalue: < 2.2e16