Which economic indicator measures the change in prices of specific goods and services over time?

Prices for products became more affordable as a result of new forms of ,witch got things to market faster and cheaper

According to the federal regulations, which of the following studies meets the definition of research with human subjects? a. a researcher uses the customs office’s passenger lists for ships bringing immigrants to the us between 1820-1845 to track the numbers of immigrants from certain ethnic groups.b. a researcher conducts a linguistic study of comments posted on a local public blog.c. a developmental psychologist videotapes interactions between groups of toddlers and their care givers to determine which intervention methods most effectively manage aggression.d. a researcher asks the director of a local free clinic about the number of patients in the last two years with newly diagnosed hiv/aids.

When recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous years?