Assignment Four - Percentages

1. The world's production of cocoa for a recent year was 2928 metric tons. Of this, 1969 metric tons came from Africa. (Source: World Cocoa Foundation) What percent of the world's cocoa production came from Africa?

2. In the jewelry industry, the amount of gold in a piece of jewelry is measured by the karat. Pure gold is 24 karats. If a necklace is 75% gold, how many karats is it?

3. In 1993, 248.7 million people in the United States were born in the United States, and the rest, 19.8 million were foreign born. What percentage of the total population of the US was foreign born?

4. The January 13, 2002 issue of the New York Timesreported that there were 547,867 foreign students enrolled at US colleges and universities in 2000-01 — representing a 6.4% increase from the previous year. The greatest number (59,939) of foreign students came from China. What percent of the foreign students studying in the US were from China in 2000-01?

5. Fox news reported that back-to-school spending per students was $527 in 2006. This year the amount increased to $563. What was the percentage change in back-to-school from 2006 to 2007?

6. Suppose we want to compare the price of a $51,675 E-Class Mercedes to the price of a $61,500 LS 460 Lexus. What percentage more does theLexus cost when compared to the Mercedes?

7. Suppose we want to compare the price of a $51,675 E-Class Mercedes to the price of a $61,500 LS 460 Lexus. What percentageless does the Mercedes cost when compared to the Lexus?

8. If a quantity doubles in value, its percentage change is ______.

9. If a quantitytriples in value, its percentage change is ______.

10. Last year, it was bad news: the value of your investment plunged by 50%. This year was much better: your investment increased in value by 75%. Over the two-year period, by how many percent has the value of your investment decreased?

11. The value of stocks can vary dramatically. Suppose a stock decreases in value by 50% one year. The next year it increases by 50%. By how many percent has the value of the stockdecreased over the two year period?

12. In 1994, Zaire’s per capita GNP was $125 (70% lower than it was in 1958). What was Zaire’s per capita GNP in 1958?

13. In 1996, 94,007 tons of waste was recycled in Chicago’s blue bag recycling program. In the year 2000, 296,363 tons were recycled. By how many percent did it increase from 1996 to 2000?

14. The January 14, 2002 issue of TIME magazine reported that Wal-Mart’s 3rd quarter revenues for 2001 were 600% more than its No. 2 competitor, K-Mart. What were K-Mart’s revenues during this period if Wal-Mart’s revenues were $48 billion?

15. The December 11, 2002 issue of Sports Illustrated reported that the federal spending for Olympic Games held in the United States was $610 million for the 1996 Atlanta Games and $1.5 billion for the 2002 Salt Lake City Games. (The figures have been adjusted for inflation.) How many times more federal money was spent on the Salt Lake City Games than the Atlanta Games?

16. The December 11, 2002 issue of Sports Illustrated reported that the federal spending for Olympic Games held in the United States was $610 million for the 1996 Atlanta Games and $1.5 billion for the 2002 Salt Lake City Games. (The figures have been adjusted for inflation.) By what percentis the federal spending for the Salt Lake City Games more than the Atlanta Games?

17. The December 11, 2002 issue of Sports Illustrated reported that the federal spending for Olympic Games held in the United States was $610 million for the 1996 Atlanta Games and $1.5 billion for the 2002 Salt Lake City Games. (The figures have been adjusted for inflation.) By what percent is the federal spending for the Atlanta Games less than the Salt Lake City Games?

18. The January 13, 2002 issue of the New York Timesreported that there were 547,867 foreign students enrolled at US colleges and universities in 2000-01 — representing a 6.4% increase from the previous year. How many foreign students were studying in US colleges and universities during 1999-2000?