A random sample is selected from a normal population. The population mean is μ=60 and the population standard deviation is α=15. After a treatment is given to the members of the sample, the sample mean is M=65. The sample size is n=25.
The hypothesis test:
H0: μ=60
H1: μ= <>60
α=0.05
Give reason why or why not the sample mean is sufficient to conclude that the treatment has a significant effect.