An engineer has designed a value that will regulate water pressure on an automobile engine. The valve was tested on 160 engines and the mean pressure was 4 lbs/square inch. Assume the standard deviation is known to be 0.9 if the value was designed to produce a mean pressure of 4.2 lbs is there a sufficient evidence at the 0.2 level that the valve performs below specifications? State the bulk and alternative hypotheses for the above scenario