7.6 - Interpreting Confidence Intervals

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The formula for confidence intervals remains the same:

Sample statistic ± Multiplier × Standard error

In each of the scenarios described in this lesson, the sample statistic would be the difference between the two sample groups or the sample matched pair. The multiplier would be either the z-value (proportions) or the t-value (means). Finally the standard error would be the sample standard error calculated using the formulas given above for each scenario

Interpretation Templates: You simply need to edit the level of confidence, the variable(s) of interest, the population, and the interval values.

  • When a confidence interval for comparing two groups or a matched pair includes 0, it is possible there is no (0) difference. In other words we cannot say there is a difference if 0 is in the interval.
  • When a confidence interval for comparing two groups or a matched pair does not include 0, we have evidence of a difference between because 0 (no difference) is not a reasonable estimate of the amount of difference.