Question

an engineer 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 6.8 pounds/square inch. it is believed that the valve performs above the specifications. the valve was tested on 24 engines and the mean pressure was 6.9 pounds/square inch with a variance of 1.00. a level of significance of 0.05 will be used. assume the population distribution is approximately normal. determine the decision rule for rejecting the null hypothesis. round your answer to three decimal places. answerhow to enter your answer (opens in new window) 2 points tables keypad keyboard shortcuts reject $h_0$ if $t >$

Explanation:

Step1: Calculate degrees of freedom

The degrees of freedom $df=n - 1$, where $n = 24$. So $df=24 - 1=23$.

Step2: Determine the critical - t value

We are doing a one - tailed test (since we believe the valve performs above specifications) with a significance level of $\alpha = 0.05$ and $df = 23$. Looking up in the t - distribution table, the critical t - value $t_{\alpha,df}=t_{0.05,23}$.
From the t - distribution table, $t_{0.05,23}=1.714$.

Answer:

$1.714$