sandy wrote:
Explanation
9. For 1979, find 27.5% of 18,509, which is approximately 5,090. For 2004, find 17.5% of 20,623, which is approximately 3,609. Round the numbers and reduce the ratio: \(\frac{5000}{3600}=\frac{25}{18}\), choice D.
10. Options B and C are correct.
Choice (A) is incorrect; the graph gives no information on the number of power plants constructed.
Choice (B) is correct. In 1979, coal and oil were each 26% and natural gas was 34% of total energy used, for a total of 68%. In 2004, coal was 34%, natural gas was 33%, and oil was 18% of total energy used, for a total of 85%.
For choice (C), the amount of energy used from hydroelectric sources in 1979 is approximately 925 units and the amount for 2004 is approximately 203 units. You calculate these figures by using the different totals for each year and the percentage of total energy represented on the graph by hydroelectric energy. 203 is less than one fourth of 925, and thus choice (C) is valid.
Choice (B) incorrect since In 1979, coal and oil were each 26% and natural gas was 34% of total energy used, for a total of """86%"""". In 2004, coal was 34%, natural gas was 33%, and oil was 18% of total energy used, for a total of 85%.