Well, we know that the rock band receives 1/3 of the profits from sales of sweaters and T-shirts, so in this case, $726 was 1/3 of the profit for that particular concert.
Using this information, we know that is we multiply 1/3 by 3 we get 1 whole, so we also multiply $726 by 3 to get the value of all the profits:
$726×3= $2178
So, if $2178 was the total value of the profits and T-shirt profits were worth $1632, then the value of sweatshirt profits was $2178-$1632= $546
Therefore, your answer is $546