An engineer has designed a valve that will regulate water pressure on an automobile engine. The valve was tested on 150150 engines and the mean pressure was 6.36.3 lbs/square inch. Assume the standard deviation is known to be 0.60.6. If the valve was designed to produce a mean pressure of 6.26.2 lbs/square inch, is there sufficient evidence at the 0.020.02 level that the valve does not perform to the specifications?
State the null and alternative hypotheses for the above scenario.
Ho:
Ha:
| null hypothesis:Ho μ | = | 6.2 | |
| Alternate Hypothesis:Ha μ | ≠ | 6.2 | |
below are details of test:
| for 0.02 level with two tail test , critical z= | 2.33 | ||
| Decision rule:reject Ho if absolute test stat|z|>2.326 | |||
| population mean μ= | 6.2 | ||
| sample mean 'x̄= | 6.300 | ||
| sample size n= | 150.00 | ||
| std deviation σ= | 0.600 | ||
| std error ='σx=σ/√n= | 0.0490 | ||
| test stat z = '(x̄-μ)*√n/σ= | 2.04 | ||
fail to reject Ho
Get Answers For Free
Most questions answered within 1 hours.