True or False: Your population mean used to be 6.0. The population standard deviation is 9. The sample size is 9. The sample mean is 7.0. .05 is your level of significance. The null hypothesis is that the population mean is less than or equal to 6.0, use your sample data to test this claim. If you use this information, you will reject the null hypothesis that the population mean is less than or equal to 6.0.
Step by step method for testing the hypothesis under 5 step approach is discussed here.