Answer:
The critical region would be 
If we compare the p value and a significance level given 
we see that 
so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 5.1 pounds/square inch at 10% of significance.
Step-by-step explanation:
Data given and notation
represent the average score for the sample
represent the population standard deviation
sample size
represent the value that we want to test
represent the significance level for the hypothesis test.
z would represent the statistic (variable of interest)
represent the p value for the test (variable of interest)
State the null and alternative hypotheses.
We need to apply a one upper tailed test.
What are H0 and Ha for this study?
Null hypothesis: 
Alternative hypothesis :
Compute the test statistic
The statistic for this case is given by:
(1)
z-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".
Calculate the statistic
We can replace in formula (1) the info given like this:
Critical value
On this case since we have a right tailed test we need to look into the normal standard distribution and find a value that accumulates 0.1 of the area on the right of the distribution or 0.9 of the area on the left and for this case we see that 
The critical region would be
Give the appropriate conclusion for the test
Since is a one side upper tailed test the p value would be:
Conclusion
If we compare the p value and a significance level given we see that so we can conclude that we have enough evidence to reject the null hypothesis, so we can conclude that the true mean is higher than 5.1 pounds/square inch at 10% of significance.
