A major car manufacturer wants to test a new catalytic converter to determine whether it meets new air pollution standards. The mean emission of all converters of this type must be less than 20 parts per million of carbon. Ten (10) converters are manufactured for testing purposes and their emission levels are measured with a mean of 17.17 and a standard deviation of 2.98. Assume measurements are normally distributed.

Hint: Rejecting the null hypothesis will make the manufacturer happy as it will show that standards are being met.

The null and alternative hypotheses to support the claim that the mean emission level for all converters of this type is less than 20 ppm is _____.

Select one:

a.H0: 20 vs.Ha: < 20

b.H0: 20 vs.Ha: = 20

c.H0: = 20 vs.Ha: 20

d.H0: 17.17 vs.Ha: < 17.17

e.H0: 20 vs.Ha: > 20