A multiple regression model Y^=?^0+?^1X1+?^2X2+?^3X3 is fit to a data set with 14 observations. If a 95% confidence interval for the mean response at X1=2,X2=?4,X3=7 is (?1,1), and a 95% prediction interval for a new observation at X1=2,X2=?4,X3=7 is (?2,2), then to three decimal places the mean square error (MSE) equals