Curtis Troxell worked for HH Appliances in Merced, and as a part of his regular duties, ran errands for his employer.

Curtis Troxell worked for H&H Appliances in Merced, and as a part of his regular duties, ran errands for his employer. Troxell was directed to drop some mail at the post office on his way home from work. After delivering the mail, he headed for Atwater to have dinner at his parents' home. He retraced his route to the post office and proceeded beyond H&H Appliances a few blocks and struck John Felix. Felix sued H&H Appliances on respondeat superior for the negligent act of employee Troxell.  

Please define respondeat superior. Was Troxell acting within the scope of employment at the time of the accident? Why or why not