An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on

240 engines and the mean pressure was

4.6 lbs/square inch. Assume the variance is known to be

0.81. If the valve was designed to produce a mean pressure of

4.7 lbs/square inch, is there sufficient evidence at the

0.02 level that the valve does not perform to the specifications?

State the null and alternative hypotheses for the above scenario.

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