formula 'bwt~lwt+age+ (race)smoke bwt_model ols(formula data=bwtfit (print bwt_model summary ()ols regression results =====================================================================dep variable bwt rsquared model ols adj rsquared method least squares fstatistic no observations prob (fstatistic ) - df residuals log likelihood - df model aic bic ====================================================================coef std err >| [ intercept (race )[ - - - - (race )[ - - - - smoke - - - - lwt age - - - =====================================================================omnibus durbin watson probomnibus ) jarque -bera (jb ) skew- prob(jb ) kurtosis cond no given the result of fisher' global test given by prob ( -statisticin the summary ( -value - )we can conclude that at least one of the explanatory variables is associated with child weight at birthafter adjusting for the other variables the individual student tests indicate thatthe mother' weight is linearly associated with child weightafter adjusting for ageraceand smoking status ( -value at the same ageraceand smoking statusan increase of one pound in the mother' weight corresponds to an increase of in the average child weight at birththe age of the mother is not significantly linearly associated with child weight at birthwhen mother weightraceand smoking status are already taken into account ( -value )weight at birth is significantly lower for child born to mother who smokescompared to children born to non-smoking mothers of the same ageraceand weightwith -value of (to see thisinspect bwt_model pvaluesat the same ageraceand mother weightthe child' weight at birth is less for smoking mother than for non-smoking motherregarding the interpretation of the variable racewe note that the first level of this categorical variable corresponds to white mothers the estimate of - for (race)[ represents the difference in the child' birth weight between black mothers and white mothers (reference group)and this result is significantly different