Looking at this stacked bar chart problem, you're dealing with two different types of calculations - a percentage increase over time and finding the largest absolute change. Let me walk you through how to tackle each part efficiently.
Part 1: Percent Increase for Model Y (2006 to 2010)Let's think about what we need here. You're looking for Model Y's growth, and the key phrase is "rounded to the nearest 5 percent" - this tells us we can work with approximations.
Looking at the chart:
- Model Y in 2006: 139 (remember, it's in thousands, so 139,000)
- Model Y in 2010: 215 (or 215,000)
Here's how you calculate the percent increase:
\(\text{Percent Increase} = \frac{\text{Final} - \text{Initial}}{\text{Initial}} \times 100\)
\(= \frac{215 - 139}{139} \times 100 = \frac{76}{139} \times 100\)
Notice how \(\frac{76}{139}\) is a bit more than \(\frac{1}{2}\) (since \(\frac{139}{2} = 69.5\)), so we're looking at something slightly above 50%.
Computing: \(\frac{76}{139} \approx 0.547\), which gives us about 54.7%
Rounded to the nearest 5%:
55%Part 2: Greatest Increase from 2007 to 2008For this part, you need to check
all six models and find which had the biggest jump. Here's what you need to see - we're looking for absolute increase, not percentage.
Let me show you the key comparisons:
- Model Z: Goes from 779 to 896 → increase of 117 thousand
- Model Y: Goes from 152 to 178 → increase of 26 thousand
- Model X: Goes from 93 to 115 → increase of 22 thousand
- Model V: Actually
decreases from 220 to 167
The winner is clearly
Model Z with an increase of 117,000 units - that's more than 4 times larger than any other model's growth!
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You can check out the
step-by-step solution on Neuron by e-GMAT to master the complete framework for handling stacked bar charts and discover the pattern recognition techniques that apply to all data interpretation questions. You can also explore other GMAT official questions with detailed solutions on Neuron for structured practice
here.