A research engineer for a tire manufacturer is investigating tire life for a new rubber compound. She has built 10 tires and tested them to end of life in a road test. The sample mean and standard deviation are 61492 and 3035 kilometers, respectively.

a) The engineer would like to demonstrate that the mean life of this new tire is in excess of 60000km. Formulate and test appropriate hypotheses, being sure to state (test, if possible) assumptions and draw conclusions using P-value approach.

c) Find a 95% one sided lower confidence bound on mean tire life.

d) Use the bound found in part (c) to test the hypothesis