It is known that the amount of time needed to change the oil on a car is normally distributed with a standard deviation of 3 minutes. A random sample of 110 oil changes yielded a sample mean of 29 minutes. Compute the 90% confidence interval estimate for the population mean. Note: For each confidence interval, enter your answer in the form (LCL, UCL). You must include the parentheses and the comma between the confidence limits.
Confidence Interval =?