Answer:
If the calculated value is less than the critical value we reject the null hypothesis.
P value
The p value for this test would be:
Since the p value is lower than the significance level given we have enough evidence to reject the null hypothesis at the 25 of significance level given.
Step-by-step explanation:
Information given
represent the sample mean
represent the population deviation
sample size
represent the value that we want to check
represent the significance level for the hypothesis test.
z would represent the statistic
represent the p value for the test
System of hypothesis
We want to check if the mean pressure is less then 7.6 pounds/square inch, the system of hypothesis are:
Null hypothesis:
Alternative hypothesis:
The statistic would be:
(1)
Replacing the values we got:
Critical value
we need to find a critical value who accumulates 0.02 of the area in the left of the normal standard distribution and we got:
If the calculated value is less than the critical value we reject the null hypothesis.
P value
The p value for this test would be:
Since the p value is lower than the significance level given we have enough evidence to reject the null hypothesis at the 25 of significance level given.