Question

An engineer has designed a valve that will regulate water pressure on an automobile engine. The engineer designed the valve such that it would produce a mean pressure of 6.4 pounds/square inch. The valve was tested on 24 engines and the mean pressure was 6.6 pounds/square inch with a standard deviation of 0.7. Is there evidence at the 0.05 level that the valve does not perform to the specifications? Assume the population distribution is approximately normal. Step 1 of 5: State the null and alternative hypotheses. Answer Point E Tables Keypad HO: Ha:

Answer 1

Date Page Solution:- Given that, x = 6.6 s = 0.7 n = 24 u=6.4 x = 0.05 The null and altemative hypothesis, Ho: u 6.4 Hail & 6.4 This is two- tailed test. Test statistic, t X-1 s/n t = 6.6 6.4 0.7/24 t 1.400 The test statistic t = 1.400 d=0.05 = N-1 24-1 = 23 df = ta; df a to.05;24 +/- 2.069

Page Reject Ho if t > 2.069 The critical Value +/-2.069 1. 400 > +/-2.069 Test statistic > Critical Value fail to Reject the null hypothesis.