Problem
- Save \& Exit Certify Lesson: 10.4c Testing a Hypothesis about a... TRISH CARDWELL Question 3 of 13, Step 5 of 6 6/18 2 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 6.5 pounds/square inch (psi). Assume the population standard deviation is 1.0 . If the valve was designed to produce a mean pressure of 6.6 psi, is there sufficient evidence at the 0.05 level that the valve performs below the specifications? Step 5 of 6 : Identify the level of significance for the hypothesis test. Answer How to enter your answer (opens in new window) Tables Keypad Keyboard Shortcuts Previous step answers Keypad
Solution
Step 1 ：The level of significance for the hypothesis test is 0.05. This is the probability of rejecting the null hypothesis when it is true. It is also known as the Type I error rate. In this case, the engineer is testing the hypothesis that the valve performs below the specifications, and the level of significance is the probability that he incorrectly concludes that the valve performs below the specifications when it actually meets or exceeds the specifications.
