A trivia tournament organizer wanted to study the relationship between the number of points a team scores in a trivia...
GMAT Problem-Solving and Data Analysis : (PS_DA) Questions
A trivia tournament organizer wanted to study the relationship between the number of points a team scores in a trivia round and the number of hours that a team practices each week. For the study, the organizer selected 55 teams at random from all trivia teams in a certain tournament. The table displays the information for the 40 teams in the sample that practiced for at least 3 hours per week.
| Hours practiced | Number of points per round | Total | |
|---|---|---|---|
| 6 to 13 points | 14 or more points | ||
| 3 to 5 hours | 6 | 4 | 10 |
| More than 5 hours | 4 | 26 | 30 |
| Total | 10 | 30 | 40 |
Which of the following is the largest population to which the results of the study can be generalized?
All trivia teams in the tournament that scored 14 or more points in the round
The 55 trivia teams in the sample
The 40 trivia teams in the sample that practiced for at least 3 hours per week
All trivia teams in the tournament
1. TRANSLATE the sampling information
- Given information:
- Organizer selected 55 teams at random from all trivia teams in the tournament
- Table shows data for 40 teams that practiced \(\geq 3\) hours per week
- Four answer choices about different populations
2. INFER the key statistical principle
- The crucial insight: When determining generalization scope, focus on the original sampling method, not the data presented
- Random sampling allows generalization back to the original population
- The sampling frame was 'all trivia teams in the tournament'
3. INFER why the table subset doesn't matter
- The table shows only 40 teams (those practicing \(\geq 3\) hours), but this is just a subset of the data
- The original sample of 55 teams was still drawn randomly from all tournament teams
- Generalization scope depends on where the sample came from, not which data gets displayed
4. Apply the generalization principle
- Since sample was drawn from 'all trivia teams in the tournament'
- Results can be generalized to 'all trivia teams in the tournament'
- This matches Choice D
Answer: D. All trivia teams in the tournament
Why Students Usually Falter on This Problem
Most Common Error Path:
Weak INFER skill: Students focus on the 40 teams shown in the table instead of the original sampling method. They think, 'The study only shows data for 40 teams who practiced at least 3 hours, so results only apply to teams like these.' This surface-level reading misses that generalization depends on the original sampling frame (all tournament teams), not the subset of data presented.
This may lead them to select Choice C (The 40 trivia teams in the sample that practiced for at least 3 hours per week)
Second Most Common Error:
Poor TRANSLATE reasoning: Students misinterpret what constitutes the 'population' by focusing on the sample itself rather than where it came from. They think the 55 sampled teams are the population of interest, missing that these teams represent a broader group.
This may lead them to select Choice B (The 55 trivia teams in the sample)
The Bottom Line:
This problem tests whether students understand that statistical generalization depends on sampling method, not data presentation. The table is a red herring - what matters is that teams were randomly selected from all tournament teams.
All trivia teams in the tournament that scored 14 or more points in the round
The 55 trivia teams in the sample
The 40 trivia teams in the sample that practiced for at least 3 hours per week
All trivia teams in the tournament