An engineer has designed a valve that will regulate water pressure on an automobile engine. the valve was tested on 200 engines and the mean pressure was 5.4 pounds/square inch (psi). assume the population standard deviation is 0.8. the engineer designed the valve such that it would produce a mean pressure of 5.5 psi. it is believed that the valve does not perform to the specifications. a level of significance of 0.05 will be used. find the value of the test statistic. round your answer to two decimal places.

-1.77

Step-by-step explanation:

Let be the population mean.

Given : The engineer designed the valve such that it would produce a mean pressure of 5.5 psi.  It is believed that the valve does not perform to the specifications.

Then ,

Since , the alternative hypothesis is two-tailed , so the test is a two tailed test.

Also. sample size :

Sample mean :

Test statistic for population mean :-

hi there!

question 1 answer: p/q can be terminating when q = 5^m * 2^n

question 2 answer: -1 and -1

question 3 answer: -4

question 4 answer: 5/12

hope this : )