Answer:
The total sales during the promotion is $69.6
Explanation:
we are given
The average daily sales at a bookstore was(7.6k + 2.2) dollars over a 4-day promotion
we have to find total sales during 4 days
so, we can integrate it to find total sales

now, we can solve it



now, we can plug bounds
and we get


So,
the total sales during the promotion is $69.6