Question

an engineer has designed a valve that will regulate water pressure on an automobile engine. the valve was tested on 180 engines and the mean pressure was 5.4 pounds/square inch (psi). assume the population standard deviation is 0.9. if the valve was designed to produce a mean pressure of 5.2 psi, is there sufficient evidence at the 0.05 level that the valve performs above the specifications? step 3 of 6: specify if the test is one - tailed or two - tailed. answer 1 point tables keypad keyboard shortcuts one - tailed test two - tailed test

Explanation:

Step1: Identify the claim

We want to test if the valve performs above the specifications (mean pressure of 5.2 psi). The alternative hypothesis is $H_1:\mu> 5.2$.

Step2: Determine test - type

When the alternative hypothesis has a '>' or '<' sign, it is a one - tailed test. Since our alternative hypothesis is $H_1:\mu > 5.2$, it is a one - tailed test.

Answer:

One - Tailed Test