Call Ratings1 Star2 Stars3 Stars4 StarsTotalEmployee A1649728145Employee B410223470Employee C8564516125Employee D22428412160Total5015722370500A superv...
GMAT Problem-Solving and Data Analysis : (PS_DA) Questions
Call Ratings
| 1 Star | 2 Stars | 3 Stars | 4 Stars | Total | |
|---|---|---|---|---|---|
| Employee A | 16 | 49 | 72 | 8 | 145 |
| Employee B | 4 | 10 | 22 | 34 | 70 |
| Employee C | 8 | 56 | 45 | 16 | 125 |
| Employee D | 22 | 42 | 84 | 12 | 160 |
| Total | 50 | 157 | 223 | 70 | 500 |
A supervisor at a call center reviewed 500 calls taken by four employees and rated the employees' performance on each call on a scale from 1 star to 4 stars. The ratings for each employee are shown in the table above. According to the table, to the nearest whole percent, what percent of Employee A's calls received a rating of 1 star?
3%
11%
16%
32%
1. TRANSLATE the question requirements
- Question asks: "What percent of Employee A's calls received a rating of 1 star?"
- This means we need: \(\mathrm{(Employee\ A's\ 1\text{-}star\ calls / Employee\ A's\ total\ calls) \times 100}\)
2. TRANSLATE the table information
- From the table, locate Employee A's row:
- 1-star calls: 16
- Total calls: 145
3. SIMPLIFY the percentage calculation
- Set up the fraction: \(\frac{16}{145}\)
- Calculate: \(16 \div 145 = 0.1103...\) (use calculator for accuracy)
- Convert to percentage: \(0.1103... \times 100 = 11.03...\%\)
- Round to nearest whole percent: 11%
Answer: B. 11%
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak TRANSLATE skill: Students confuse what represents the "part" and what represents the "whole"
Instead of using Employee A's total calls (145) as the denominator, they might use:
- The total of all calls (500), calculating \(\frac{16}{500} = 3.2\% \approx 3\%\)
- Or they use the total 1-star calls across all employees (50), calculating \(\frac{16}{50} = 32\%\)
This leads them to select Choice A (3%) or Choice D (32%) respectively.
Second Most Common Error:
Inadequate TRANSLATE reasoning: Students stop at finding the raw number instead of converting to percentage
They see that Employee A had 16 one-star calls and think this directly corresponds to 16%, leading them to select Choice C (16%).
The Bottom Line:
Success on this problem requires carefully identifying what group you're finding the percentage within (Employee A's calls only) and what you're measuring (the 1-star calls within that group).
3%
11%
16%
32%