Answer:
First, let’s calculate the money Sam makes per week, not including sales (or assuming $0 in sales):
money per week =$6.45/hour×37.5hours/week=$241.88/week
The money he gains from sales must make up the difference, so
money from sales =$400−$241.88=$158.12
This money is only 6% or 0.06 of the total sales though, so
total sales =$158.120.06=$2635.33
Of course, this is assuming that the money per week is rounded up from $241.875 to $241.88 instead of down to $241.87, in which case Sam would have to make $2635.50 in sales (about 17 cents more).
