An engineer designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 5.0 pounds/square inch. The valve was tested on 170 engines and the mean pressure was 5.1 pounds/square inch. Assume the variance is known to be 0.81. Is there evidence at the 0.05 level that the valve performs above the specifications?

1)Enter the hypotheses:

2)Enter the value of the z test statistic. Round your answer to two decimal places.

3)Specify if the test is one-tailed or two-tailed.

4)Enter the decision rule.

5)Enter the conclusion.