In which year was the production of hydro and nuclear electricity almost twice…
2013
In which year was the production of hydro and nuclear electricity almost twice the combined production of crude petroleum and natural gas?
Answer: C. 2008–09 — ConceptWhen one quantity is almost double another, compare their ratio with 2. If E is the first quantity and C is the comparison quantity, the best match has…
- A.
2006–07
- B.
2007–08
- C.
2008–09
- D.
2009–10
Show answer & explanation
Correct answer: C
Concept
When one quantity is almost double another, compare their ratio with 2. If E is the first quantity and C is the comparison quantity, the best match has the smallest normalized deviation |E ÷ C − 2|.
Application
Let C be the combined production of crude petroleum and natural gas, and let E be the production of hydro and nuclear electricity. Compute E ÷ C for every offered year.
Year | Combined petroleum and gas, C | Hydro and nuclear electricity, E | Ratio E ÷ C |
|---|---|---|---|
2006–07 | 1,423 + 1,223 = 2,646 | 4,763 | 4,763 ÷ 2,646 ≈ 1.80 |
2007–08 | 1,429 + 1,248 = 2,677 | 4,944 | 4,944 ÷ 2,677 ≈ 1.85 |
2008–09 | 1,403 + 1,265 = 2,668 | 5,133 | 5,133 ÷ 2,668 ≈ 1.92 |
2009–10 | 1,411 + 1,830 = 3,241 | 4,511 | 4,511 ÷ 3,241 ≈ 1.39 |
Cross-check
The ratio 1.92 for 2008–09 is the closest to 2. As a direct cross-check, twice its combined production is 2 × 2,668 = 5,336, only 203 peta joules above 5,133; the other ratios differ from 2 by larger amounts. Therefore, the required year is 2008–09.