Final answer:
The cost of bananas at a grocery store is calculated by multiplying the quantity of bananas by the price per item. If bananas are $3 each, buying 4 bananas would cost $12 in total.
Step-by-step explanation:
When computing the cost of bananas sold at a grocery store for three dollars per quantity, we use the concept of scale factors to determine the total price for any given amount of bananas. For instance, if you buy one item, it will cost you $3. If you buy two, you multiply 2 (the quantity) by $3 (the price per item), resulting in a total of $6. So, for every additional item purchased, you continue to multiply the number of items by the price per item to get the total cost.
Let's say you want to buy 4 bananas. Using the scale factor, that would be 4 (the number of bananas) × $3 (the price per banana), equating to a total of $12 spent on bananas. This kind of mathematics is essential for managing personal finances and understanding how prices scale with quantity.