4. Let's say you own a piece of art that increases in value by 50% the first year after you buy it. 20% the second year. and 90% the third year. What was the increase of that piece of art on average? What type of average do you have to use? Solution: around 50,66%, using the geometric mean.

Stock Market During the week of June 22, 2009, the closing numbers of the Dow Jones Industrial Average each day were: What was the overall change for the week? Was it positive or negative?

A manufacturer estimates that 15,500 pieces per day could be produced with the installation of new machinery. The machines now used produce 11,000 pieces per day. What percent increase in production would be gained by replacing the present machinery with new machinery? Round the answer to the nearest whole percent.

Use this data for the exercises that follow: In 2013, there were roughly 317 million citizens in the United States, and about 40 million were elderly (aged 65 and over).[34] 56. If you meet a U.S. citizen, what is the percent chance that the person is elderly? (Round to the nearest tenth of a percent.)