Following the same logic of a level C = (1 – α) ⋅ 100% confidence interval, we use the standard formula:
point estimate ± margin of error
Before we jump to the confidence interval formula, we need to see a bit of notation. The population mean difference in the two data sets is denoted by μd, and we represent the sample mean difference in the two data sets by d̄. The standard deviation of the difference in the two data sets is represented by sd.
Our point estimate of μd is, thus, d̄. The formula for a level C = (1 – α) ⋅ 100% confidence interval is
which, in interval notation, is:
