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AP Statistics 3.11.B Justifying Claims from Difference Intervals

Practise using confidence intervals for differences in population proportions to evaluate claims, check whether zero is plausible, and bound two-sided p-values.

Syllabus
Effective Fall 2026
Course
AP Statistics

Exam points

  • Use whether zero lies in a difference interval to decide if data support a population difference.
  • Relate nested confidence intervals to p-value bounds for a two-sided hypothesis test.

3.11.B—Justify a claim based on a confidence interval for the difference between two population proportions question 1

[Maximum number: 1]

Researchers from a national research organization investigated which platform (television, social media, newspaper, In ternet, etc.) United States adults prefer to use to obtain their news. In 2016, of the 200 randomly selected United States adults that were surveyed, 114 selected television as their preferred platform. In 2018, of the 200 randomly selected United States adults that were surveyed, 98 selected television as their preferred platform. The conditions for inference are met. A 95 percent confidence interval for the difference in the population proportions of United States adults that use television as their preferred platform for obtaining news between 2016 and 2018 (2016 minus 2018) was found to be (-0.02, 0.18). Based on the interval, is it reasonable for the researchers to claim that there is convincing statistical evidence that the population proportion of United States adults that use television as their preferred method to obtain news differed between 2016 and 2018?

A

No, because the researchers should have used a greater confidence level to obtain convincing evidence.

B

No, because zero is included in the interval there is not convincing statistical evidence that the population proportion differed between 2016 and 2018.

C

Yes, because zero is included in the interval there is convincing statistical evidence that the population proportion differed between 2016 and 2018.

D

Yes, because most of the interval is positive there is convincing statistical evidence that the population proportion increased from 2016 to 2018.

E

Yes, because 0.57 is greater than 0.49 there is convincing statistical evidence that the population proportion decreased from 2016 to 2018.

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