Another type of confidence interval is called a one-sided confidence interval. A one-sided confidence interval provides either a lower confidence bound or an upper confidence bound for the parameter in question. You are asked to examine one-sided confidence intervals.

Presuming that the assumptions for a one-mean t-interval are satisfied, we have the following formulas for (1 − α)-level confidence bounds for a population mean μ:

Lower confidence bound: X - 1_a - s/√n

Upper confidence bound: X + t_{a - S/√n}

Interact the preceding formulas for lower and upper confidence bounds in words.