Store Receipt is an example of a dot product

You bought some items at a store and paid a total bill.
The total calculation an example of a dot product.
P = price
Q = quantity
Total = (P1 * Q1) + (P2 * Q2)… + (PN * QN)
The price of item1 times the quantity of item1
plus the price of item2 plus the quantity of item2 etc
and then add them all up to a total that you pay.
Congrats! that’s what a dot product is except use W and A
instead of P and Q.

Thanks for your report.