The manager at a drive through has implemented a new process and wants to check if the new drive through process has a mean less than XXXXXXXXXXseconds. The overall std. deviation of all the stores...

The manager at a drive through has implemented a new process and wants to check if the new drive through process has a mean less than 188.83 seconds. The overall std. deviation of all the stores across the globe is 20 seconds. He has taken a sample of 39 and found the mean time to be 186.90 seconds. What does the hypothesis test lead to? Is there evidence to suggest the process has really improved?