Question

An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 170 engines and the mean pressure was 4.7 pounds/square inch (psi). Assume the population variance is 1.00. If the valve was designed to produce a mean pressure of 4.5 psi, is there sufficient evidence at the 0.05 level that the valve does not perform to the specifications?

Step 5 of 6:

Identify the level of significance for the hypothesis test.

Answer 1

Solution:

1)

H₀ : = 4.7 vs H_a: 4.7

2)

The test statistic t is

z = ( - )/[/n] = [4.5 - 4.7]/[1.00/170] = 2.61

z = 2.61

5)

Level of significance is

0.05