An international health organization collected global data regarding a certain disease for each of 14 consecutive years (Y1 – Y14)....
GMAT Graphics Interpretation : (GI) Questions
An international health organization collected global data regarding a certain disease for each of 14 consecutive years (Y1 – Y14). The graph shows the annual numbers of cases, countries, countries with local cases (i.e., cases for which the infection was contracted within the country), and countries with non-local cases (i.e., cases for which the infection was contracted outside of the country).
From each drop-down menu, select the option that creates the most accurate statement according to the information provided.
Owning the Dataset
Table 1: Text Analysis
| Text Component | Literal Content | Interpretation |
|---|---|---|
| Data Collector | An international health organization | Reputable, global data source |
| Subject | Collected global data regarding a certain disease | Study focuses on one disease, not named |
| Time Frame | Each of 14 consecutive years \(\mathrm{(Y1–Y14)}\) | Annual data, labeled Y1 to Y14, over 14 years |
| Annual Cases | Annual numbers of cases | Total number of disease cases reported each year |
| Countries | Annual numbers of countries | How many countries reported disease occurrence annually |
| Local Cases | Countries with local cases (infection contracted within the country) | Countries with in-country transmission |
| Non-local Cases | Countries with non-local cases (infection contracted outside the country) | Countries with travel/imported cases |
Table 2: Chart/Graph Analysis
| Chart Element | What it Shows | Interpretation |
|---|---|---|
| Chart Type | Combination bar and line chart, dual Y-axes | Multiple data types visualized; direct time series comparison |
| X-Axis | Years \(\mathrm{Y1−Y14}\) | 14-year timeline, aligns with text description |
| Left Y-Axis | \(\mathrm{0–700}\) (in thousands, for cases) | Disease case counts (e.g., up to 600,000) |
| Right Y-Axis | \(\mathrm{0–70}\) (for countries) | Number of affected countries (max observed ≈ 59) |
| Blue Bars | Case numbers per year | Visualizes fluctuations, particularly a major spike in Y12 |
| Solid Line | Total countries affected each year | Shows stable range (about 45–59 countries/year) |
| Dashed Line | Countries with local cases per year | Usually just below total countries; most cases are local |
| Y12 Spike | Large increase in blue bar | Dramatic uptick in cases without rise in affected countries |
Key Insights
- The number of disease cases fluctuates dramatically, particularly with a sharp spike in year Y12 (from ~200,000 to ~600,000 cases), while the number of affected countries remains largely stable.
- A consistently small gap between total countries and countries with local cases suggests most transmission occurs within national borders, not via international travel.
- Despite intense outbreaks (as in Y12), geographic spread remains contained: the disease intensifies in certain locations but does not expand to many more countries.
- The early years (Y1–Y5) feature slowly declining cases and nearly stable country counts, indicating a baseline before later outbreaks.
Step-by-Step Solution
Question 1: Percent Increase in Cases from Y9 to Y12
Complete Statement:
The percent increase in the number of cases of the disease from Y9 to Y12 was, to the nearest 10%, ______.
Breaking Down the Statement
- Statement Breakdown 1:
- Key Phrase: percent increase
- Meaning: The amount by which something grows, shown as a percentage compared to its starting value.
- Relation to Chart: Compare the height of the bars for Y9 and Y12, since those represent cases for those years.
- Important Implications: Requires the formula: \(\frac{\mathrm{final - initial}}{\mathrm{initial}} \times 100\%\).
- Statement Breakdown 2:
- Key Phrase: from Y9 to Y12
- Meaning: The starting year is Y9, and the ending year is Y12.
- Relation to Chart: Locate Y9 and Y12 along the x-axis and use their respective bar heights.
- Important Implications: It's important to use only those two years' data and ignore any in between.
What is needed: The percentage increase in disease cases from Y9 to Y12, rounded to the nearest 10%.
Solution:
- Condensed Solution Implementation:
Use the bar values for Y9 and Y12 and apply the percent increase formula. - Necessary Data points:
Cases in Y9: 200,000; Cases in Y12: 600,000. - Calculations Estimations:
Percent increase = \(\frac{600,000 - 200,000}{200,000} \times 100\% = \frac{400,000}{200,000} \times 100\% = 2 \times 100\% = 200\%\). - Comparison to Answer Choices:
200% is one of the available answer choices and matches exactly.
FINAL ANSWER Blank 1: 200%
Question 2: Average Countries with Local Cases from Y1 to Y5
Complete Statement:
The average (arithmetic mean) of the numbers of countries with local cases from Y1 to Y5 was, to the nearest 5 countries, ______.
Breaking Down the Statement
- Statement Breakdown 1:
- Key Phrase: average (arithmetic mean)
- Meaning: Sum all values, then divide by count to get the mean.
- Relation to Chart: Extract numbers for Y1 through Y5 from the dashed line (countries with local cases).
- Statement Breakdown 2:
- Key Phrase: countries with local cases
- Meaning: The count of countries where the disease originated locally (not imported).
- Relation to Chart: These are represented by the dashed line on the graph.
What is needed: The mean (rounded to the nearest 5) of local-cases countries from Y1 to Y5.
Solution:
- Condensed Solution Implementation:
Read the dashed line values for Y1-Y5, sum them, divide by 5, and round to the closest 5. - Necessary Data points:
Y1: 51, Y2: 50, Y3: 40, Y4: 40, Y5: 46 countries. - Calculations Estimations:
Sum = 51 + 50 + 40 + 40 + 46 = 227. Average = \(227 \div 5 = 45.4\). Rounded to nearest 5 = 45. - Comparison to Answer Choices:
Answer choices are 15, 35, 45, and 55. 45 matches our result and is between the values given.
FINAL ANSWER Blank 2: 45
Summary
For blank 1, a direct application of the percent increase formula shows cases tripled from Y9 to Y12, resulting in a 200% increase. For blank 2, averaging the first five dashed line values and rounding gives 45 countries. Both use distinct data and math.
Question Independence Analysis
The questions are independent. Blank 1 uses bar graph values (cases) and years 9 and 12, while blank 2 uses dashed line values (countries) and years 1 through 5. Solving one does not assist with the other.