An automatic coffee machine dispenses cups of coffee whose volume per cup varies normally with the mean = 10 oz.

3.) The dean of the engineering school at a technical university wants to emphasize the importance of having students who are gifted at reading and writing as well as math. She wants to know if she can accurately claim that graduate students in engineering programs at her school have significantly higher scores on the verbal reasoning section of the GRE (a standardized test used in the admissions process for many graduate programs) than the national average for engineering students. The national average for the verbal reasoning GRE score for engineering students was 150 with a standard deviation of 9. A random sample of 49 engineering graduate students at her school were found to have an average verbal reasoning GRE score of 153.

Which hypothesis test should be used to determine whether the engineering students at the dean's technical university have a higher verbal reasoning GRE score than the national average?

•  a.) z-test for the population mean

b.) t-test for the population mean

 c.) z-test for the population proportion

 d.) t-test for the population proportion