The line graph tracks the gross production of natural gas in billions

Question

https://gmatclub.com/forum/download/file.php?id=82207 The line graph tracks the gross production of natural gas in billions of cubic feet (where 1 billion = 1,000,000,000) in four countries over a period of five years. Select from each of the drop-down menus the option that creates the most accurate statement based on the information provided. In 2007, the percent growth in gas production over the 2004 level in Mexico was GRAPH_1_PLACEHOLDER that in Venezuela. The average (arithmetic mean) amount of increase in natural-gas production from 2004 to 2008 was closest to GRAPH_2_PLACEHOLDER billion cubic feet. GMAT-Club-Forum-tphv0yqh.png

chetan2u · Accepted Answer

(1) In 2007, the percent growth in gas production over the 2004 level in Mexico was _____that in Venezuela. So we have to take the % growth separately for both Mexico and Venezuela and then compare the two. a. Mexico: 1500 approx to 2000, so 500 over 1500, that is 33.33%. b. Venezuela: 2000 approx to 2500, so 500 over 2000, that is 25%. Clearly, greater than is the answer (2) The average (arithmetic mean) amount of increase in natural-gas production from 2004 to 2008 was closest to billion cubic feet. Add all in 2004 and then in 2008, find the difference and divide by 4. But I would be more comfortable in findin the difference in each. a. Mexico: 1500 approx to 1800, so 300 b. Venezuela: 2000 approx to 2500, so 500 c. Brazil: 600 to 750, so 150. d. T and T: 1050 to 1500, so 450 Add all, so 300+500+150+450 or 1400, so average will be 1400/4 or 350 . GMAT-Club-Forum-n1kc2dc5.png

pratikshyasuar · Answer

In no. 2 are we averaging increase across the 4 countries or avergaing over increase per year from 2004 to 2008

Bunuel · Answer

For the second drop-down, we are averaging  the total increase from 2004 to 2008 across the 4 countries .

The wording says “the average amount of increase in natural-gas production from 2004 to 2008,” so for each country we first find:

2008 production minus 2004 production

Then we average those four increases, meaning we add the increases for the four countries and divide by 4, the number of countries.

We are not averaging the yearly increases.

Usernamevisible · Answer

For part 2 - 
Doubt - I thought by default it means average yearly earning

Feedback
When a question says:
"The average increase in production from 2004 to 2008"
the default interpretation is:
Number of Countries
(Increase of Country A)+(Increase of Country B)+⋯
 ​
It is averaging across entities (countries), not across years.

GMAT Shortcut

When you see:
Average increase of X groups/companies/countries
→ Average across groups.

When you see:
Average annual increase / per year increase
→ Average across time.

The word "annual" is the trigger that tells you to divide by the number of years rather than the number of entities.

muskang2000 · Answer

You can also calculate 2004 total production / 4 and 2008 total production / 4 and then compute the increase

The line graph tracks the gross production of natural gas in billions

Prep Toolkit

Top 5 GMAT Debrief Videos

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards

GMAT Graphs and Tables (G&T) Questions

The line graph tracks the gross production of natural gas in billions

Prep Toolkit

615 to 715 in 15 Days (Ria's Strategies)

More than Quant/Verbal Abilities: Speed vs. Accuracy

745 with Only Self-Prep and GMAT Club

From 555 to 765: 210-point Improvement

Perfect 805 Score Debrief by Julia

My Rewards