Final answer:
Index numbers and base years are used to simplify the total quantity spent on products over a year and calculate inflation rates in finance and economics.
Step-by-step explanation:
In the context of finance and economics, index numbers and base years are used to simplify the total quantity spent on products over a year and calculate inflation rates. Index numbers are measurements that represent the average price, quantity, or value of a group of goods or services relative to a base period. A base year is the reference period against which other years are compared.
For example, if you want to calculate the inflation rate for a particular year, you would use an index number to compare the prices of goods and services in that year to the prices in a base year. This allows you to measure the change in purchasing power over time.