However, there were actually 270 responses to the above class survey. One student claimed to study 30,000 minutes per night. We know he's joking, so we left out this value. If we did a calculation without looking at the data, we would get x = 248 minutes for all 270 students.
Now what is the 99% confidence interval for the population mean? Continue to use σ = 65. Compare the new interval with the result that ignores the outlier.