Compute a 95% confidence interval for the population mean, based on the sample numbers 21, 28, 33, 34, 25, 26, and 135.

Find the lower and upper limits of the interval.

Lower – 15.449; Upper – 67.174

Lower – 20.492; Upper – 40.876

Lower – 18.925; Upper – 50.741

Lower – 5.449; Upper – 80.837