An engineer has 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 7.77.7 pounds/square inch. The valve was tested on 2424 engines and the mean pressure was 7.47.4 pounds/square inch with a standard deviation of 0.70.7. Is there evidence at the 0.0250.025 level that the valve performs below the specifications? Assume the population distribution is approximately normal.

Step2of5:

Find the value of the test statistic. Round your answer to three decimal places.