How much money did jahleel earn during his shift

First, add up the 4 sales J. made:  1200+2350+975+375 = 4900 (dollars).
He receives a 4% commission on sales, which here is 0.04($4900) = $196.

His hourly earnings are ($12.75)(x), and x = 6 hours here; thus:  $76.50

Add together his earnings ($76.50) and his commission income ($196).

Result:  $76.50 + $196 = $272.50            was his income for the day.