Verified Answer :

(# hours per day) (total days worked)= (total number of hours worked)
(total hours) 
($ amount earned per hour)= (total amount earned)= $581.25

(6.2)  (5)=31
(31) 
(18.75)= 581.25

so  6.2 hours per day for 5 days
6.2 times 5=31 hours total
and 18.75 per hour

31 times 18.75=581.25

he earned $581.25