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. Calculate the appropriate test statistic to test the hypotheses.

A. 3.00

B. 9.50

C. -0.95

D. -3.00

E. -9.50

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. What is the critical value for a = .01 to test the hypotheses.

A. -2.821

B. -3.250

C. -2.33

D. 2.821

E. 3.250

Last year, during an investigation of the time spent reading e-mails on a daily basis,

researchers found that on Monday the average time was 50 minutes. Office workers claim that

with the increased spam and junk mail, this time has now increased. To conduct a test, a

sample of 25 employees is selected with the following results: sample mean = 51.05 minutes

and sample standard deviation = 4.42 minutes. Calculate the appropriate test statistic to test

the hypothesis that the time has increased from last year.

A. 2.38

B. 1.19

C. -1.19

D. 1.76

E. -1.76