Question: A senior executive of an Australian company in Hangzhou is interested in marketing his high-quality steel-belted radial truck tires in Europe. The company believes the average kilometer the tire can be driven before tread wears out is over 70,000 kilometers. Based on historical records, the life expectancy of tires appears to be a normally distributed random variable. The European Consumer Centre (ECC) randomly selected a sample of 18 tires and recorded the number of kilometers each tire lasted before tread wears out. The recorded kilometers for these 18 tires is listed below:

a. Using a 0.10 level of significance, do you find statistical support for the senior executive’s claim?

b. Construct a 95% confidence interval for the life expectancy of tires to test the hypothesis for part (a).

c. Use the excel function to find the p-value. Interpret your p-value.

d. Use SPSS to test the senior executive’s claim and compare your computer results (printout) with your answers to previous parts.