QUESTION 1 [40]

Suppose the measures to ensure that all manufactured motor vehicles meet requirements with regards to carbon monoxide emission indicate that the standard deviation per unit volume of exhaust fumes must not be in excess of 0.03 percent carbon monoxide emission particles per unit volume. A random sample of ten newly manufactured motor vehicles are tested and the following carbon monoxide emissions are recorded:

0.23/ 0.27 /0.31 /0.25 /0.30 /0.29/ 0.32 /0.26 /0.24 /0.22

a) Calculate the point estimate of the standard deviation of the carbon monoxide

emissions.

b) What is the 99% confidence interval estimate for the population variance of the

carbon monoxide emissions

c) Provide an interpretation for the answer in b).

d) Suppose the level of confidence is reduced, what will happen to the answer in b)?

Motivate.

e) Use the critical value approach and test a hypothesis at a 5% level of significance to determine whether the requirements are met and show Hypothesis steps.