1. In 2016, B, C, E, and A had ranks 1, 2, 3, and 4 respectively.
2. F had lower SI than any other country in 2016, 2020, and 2024.
3. In 2024, E was the only country with SI of 90.
4. The range of SI of the six countries was 60 in 2016 as well as in 2024.
What was the SI of E in 2016?
60
Step-by-Step Solution
Key idea: This is a coordinate-to-fraction reverse-engineering question, recognisable because scatter plot axes represent percentage changes and the underlying values must be integers.
Why this method applies: The chart encodes multiplicative relationships visually. Since the final SI is given as exactly 90 and all SIs are integers, the percentage increases must correspond to simple fractions that preserve integrality through two successive multiplications. Visual estimation narrows candidates; integer constraints select the unique valid value.
Step 1: Calibrate the axes from grid lines.
X-axis (% increase 2016 to 2020): 0% at x=219, 20% at x=284 65 pixels = 20%.
Y-axis (% increase 2020 to 2024): 0% at y=290, 10% at y=234 56 pixels = 10%.
Step 2: Estimate E's coordinates from the plot.
E is at approximately (322, 230).
X: pixels right of 0%. units of 20% .
Y: pixels above 0%. units of 10% .
Step 3: Test simple fractions near estimates.
For X , try (33.3%). Multiplier = .
For Y , try (12.5%). Multiplier = .
Step 4: Reverse-calculate from known .
Both are integers. This confirms the fractions are correct.
Answer: 60