Question

Which data collections show bias? Check all that apply.
Ten numbered tickets were selected from a bowl containing all raffle tickets sold.
A bank asked its 25 wealthiest customers to complete a satisfaction survey.
Fifth graders were asked what desserts should be served with school lunches.
Every tenth semi-trailer was pulled over and weighed at the state border.
College students at the honors library were asked who they voted for in the last election.

Answer 1

The following data collections show bias:

1. **A bank asked its 25 wealthiest customers to complete a satisfaction survey.** - This sample is biased because it only includes the wealthiest customers, who may have different experiences and opinions than average or less wealthy customers.

2. **College students at the honors library were asked who they voted for in the last election.** - This sample is potentially biased as it only includes students who study in the honors library, which may not be representative of the entire student population.

The other data collections appear to be more random or systematic in their sampling methods, which may reduce bias:

- **Ten numbered tickets were selected from a bowl containing all raffle tickets sold.** - This is a random selection, which is less likely to introduce bias.
- **Fifth graders were asked what desserts should be served with school lunches.** - This is a targeted sample but may be appropriate for the specific question being asked and doesn't necessarily introduce bias.
- **Every tenth semi-trailer was pulled over and weighed at the state border.** - This systematic approach reduces bias by attempting to sample every tenth truck rather than focusing on a specific type.