On a number line, the directed line segment from cap q to cap s has endpoints cap q at negative 8 and cap s at 12 Point cap r partitions the directed line segment from cap q to cap s in a ratio of 4 to 1 ratio. Which expression correctly uses the formula open paren the fraction with numerator m and denominator m plus n close paren times open paren x sub 2 minus x sub 1 close paren plus x sub 1 to find the location of point cap r ?