Final answer:
To calculate the cost of 10.5 pounds of beef when 2 pounds cost $8.40, divide $8.40 by 2 to get the price per pound, which is $4.20, then multiply by 10.5 pounds to get a total cost of $44.10.
Step-by-step explanation:
The subject of this question is Mathematics, specifically dealing with proportions and unit cost calculations. If 2 pounds of ground beef cost $8.40, we first determine the price per pound by dividing the total cost by the number of pounds. So, $8.40 divided by 2 pounds gives us $4.20 per pound.
Now that we have the unit cost, we can calculate the cost for any number of pounds by simply multiplying the unit cost by the quantity desired. Therefore, to find out how much 10.5 pounds of beef would cost, we multiply the unit cost ($4.20) by 10.5 pounds. This results in a total cost of $44.10 for 10.5 pounds of beef.
It's important to understand this concept because it allows you to calculate proportional costs for different quantities of a product, which is a key skill in effective budgeting and shopping.