Lesson 17: Significance Testing with Colorado Polling Data
November 2, 2026
Review:
- Significance Testing, one-tail vs two-tail
- Exam 4 on Wed 11, Nov
Presentation:
- Statewide elections and ballot measures
- Cast a “ballot” for these 2 statewide races:
- Governor: Phil Weiser (D) vs Victor Marx (R)
- Senate: Mark Baisley (R) vs John Hickenlooper (D)
- Proportions are different
- p-hat approach for significance testing
Practice Problem – Colorado Proposition 134: The University of Colorado Boulder and YouGov surveyed 800 Colorado eligible voters between October 9 and October 20, 2026, about Proposition 134, concerning eligibility policies for school and college sports.
The poll reported: 55% support, 34% oppose, 10% undecided. Is there sufficient statistical evidence that more than half of Colorado eligible voters support Proposition 134?
Step 1. Hypotheses
- Ho : p = 0.50
- Ha : p > 0.50
Step 2. Sample proportion
- p-hat = 0.55
Step 3. Test statistic
Step 4. P-value
- P(Z > 2.83) = 0.0023
Step 5. Conclusion
- Because 0.0023 < 0.05 , we Reject Ho, the null hypothesis.
- If the participants surveyed are an unbiased representative of Colorado voters, Proposition 134 is likely to pass.
Activity:
Conduct Hypothesis Tests on the US Senate and Governor polling to determine if classroom polls are significantly different from the statewide polling conducted by the University of Colorado political climate research.
