Llantas Inc. claims that average life of certain tire is greater or equal than 25,000 miles under normal driving conditions. A random sample of 16 tires is tested. The mean of the sample is 24,000 miles and the standard deviation of the population is 4,000 miles. Use alpha = 0.05.
1. State the hypotheses H0 and H1.
2. Compute the test statistic to utilize.
3. Identify if the test is a two-tail or a one-tail-test (draw the reject/fail-to-reject zones with the critical value(s)).
4. Using any approach (Critical Value or p-value), what is your conclusion about the null hypothesis?