I have 2 columns, one showing Sales (Col B) and one showing Hours (Col A) -
This shows the Sales per Hour

How can I add up the Total Sales for a given Start Time and End Time. These
two values will be in two cells, say AA1 and AA2

Thus if AA1 said 9:30am and AA2 said 13:45am, what would be the formula that
would give me the correct answer?

Note my Hour divisions are in Qtr hour, as are my Sales values

Thanks