HO: µ = 70
H1: µ > 70
ó = 20, n = 100, xbar = 80, á = .01
a) calculate the value of the test statistic
b) set up the rejection region.
c) determine the p-value
d) interpret the results
Use the z-test formula to find the test statistic:
z = (sample mean - population mean)/(standard deviation divided by the square root of the sample size)
Plug the values given into the formula to calculate your z-test statistic.
Since the H1 shows a specific direction, this test will be one-tailed. Check z-table for the critical value (or cutoff point) to reject the null hypothesis using what is given in the problem.
If the test statistic exceeds the critical value, reject the null. If the test statistic does not exceed the critical value, you cannot reject the null.
The p-value is the actual level of the test statistic and can be found using a z-table.
I hope this will help get you started.