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Confidence Intervals for Singular Proportions

Confidence Intervals for Singular Proportions

Author: Al Greene

• Introduce the logic of confidence intervals for proportions and the meaning of confidence levels
• Present the one-proportion z-interval formula (p-hat ± z*• S ) along with critical value (z*) and margin of error (z*• S )
• Review standard error for proportions
• Review the assumptions and conditions that are necessary for confidence intervals of proportions
• Practice calculating and interpreting one-proportion z-intervals

This packet discusses how to make confidence interval for a single proportion. We review the formula, show some examples, and let you try some out on your own.

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What's in this packet

This packet shows you how to create a confidence interval for a single proportion. We have a slideshow with definitions and examples, as well as examples for you to do on your own. Some terms that may be new are:

  • Confidence Interval
  • Confidence Level
  • Critical Value
  • Margin of Error
  • One-proportion z-interval

Source: Greene


This powerpoint gives you some of the definitions of the parts of a confidence interval, as well as the commonly used Z multipliers.

Source: Greene

Confidence Interval for a Population Proportion

This video gives a good example on how to calculate a confidence interval for a singular proportion.