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 6.5 pounds/square inch. It is believed that the valve performs above the specifications. The valve was tested on 220 engines and the mean pressure was 6.6 pounds/square inch. Assume the variance is known to be 0.49. A level of significance of 0.01 will be used. Find the value of the test statistic. Round your answer to 2 decimal places.