An engineer has designed a valve that will regulate water
pressure on an automobile engine. The valve was tested on
130
engines and the mean pressure was
4.5
pounds/square inch (psi). Assume the population standard
deviation is
0.9
. The engineer designed the valve such that it would produce a
mean pressure of
4.7
psi. It is believed that the valve does not perform to the
specifications. A level of significance of
0.02
will be used. Find the value of the test statistic. Round your
answer to two decimal places.
