Using Minitab to Lighten the Workload
For any sizeable data set, and even for the small ones, you'll definitely want to use Minitab to calculate the confidence and/or prediction intervals for you. To do so:
(1) Under the Stat menu, select Stat, and then select Regression:
(2) In the pop-up window that appears, in the box labeled Response, specify the response and, in the box labeled Predictors, specify the predictor variable:
Then, click on the Options... button.
(3) In the pop-up window that appears, in the box labeled Prediction intervals for new observations, type the value of the predictor variable for which you'd like a confidence interval and/or prediction interval:
In the box labeled Confidence level, type your desired confidence level. (The default is 95.) Then, select OK.
(4) And, select OK on the main pop-up window. The output should appear in the session window. The first part of the output should look something like this:
while the second part of the output, which contains the requested intervals, should look something like this: