Stat > Basic Statistics > 1-Sample t > Options
Specify the confidence level for the confidence interval, or define the alternative hypothesis.
Confidence level: Enter the level of confidence desired. Enter any number between 0 and 100. Entering 90 will result in a 90% confidence interval. The default is 95%.
Alternative hypothesis: Enter Mean < hypothesized mean (lower-tailed), Mean hypothesized mean (two-tailed), or Mean > hypothesized mean (upper-tailed). If you choose a lower-tailed or an upper-tailed hypothesis test, an upper or lower confidence bound will be constructed, respectively, rather than a confidence interval.