This is Statistics.. Provide clean and readable solution.

A research engineer for a tire manufacturer is investigating tire life for a new rubber compound and has built 15 tires and tested them to end-of-life in a road test. The sample mean and standard deviation are 60,139.7 and 3645.94 kilometers. Find a 90% lower confidence bound for o. [Write your final answer as a decimal number, round it up to 2 decimal places]