A report in LTO stated that the average age of taxis in the Philippines is 9 years. An operation manager of a large taxi company selects a sample of 40 taxis and finds the average age of the taxis is 8.2 years. The of the population is 2.3 years. At = 0.05, can it be concluded that the average age of the taxis in his company is less than the national average?

a. State the null and alternative hypothesis

b. Level of significance and critical region

c. Compute for the value of one sample ztest.

d. Decision Rule

e. Conclusion