A single$-$phase $50-$kVA, $2400/240$ V$,60-$Hz distribution transformer is used as a step$-$down transformer at the load end of a $2400-$V feeder whose series impedance is $(1+$j$2)$ Ohms. The equivalent series impedance of the transformer is $(1+$j$2\mathrm{.}5)$ Ohms referred to the high$-$voltage side. The transformer is delivering rated load at $0\mathrm{.}8$ power factor lagging and at a rated secondary voltage. Determine the real power delivered to the sending end of the feeder in per unit. Work the problem in per$-$unit.$$