When you solve that you get 30.825 because you divided 123.3 which was your dimensions times 9 and if you divide that by 4 you get 30.825 . Let me know if that is correct if not I will find new solution!
Its a very odd prism.... hope this helps lol <span />
Answer:
y= 2,471x - 230y because each day he travels the same average distance of 230 miles