The population mean and standard deviation are given below. Find the required probability and determine whether the given sample mean would be considered unusual. For a sample of n = 67, find the probability of a sample mean being less than 21.1 if u = 21 and o = 1.3. Click the icon to view page 1 of the standard normal table. Click the icon to view page 2 of the standard normal table. For a sample of n = 67, the probability of a sample mean being less than 21.1 if u = 21 and o = 1.3 is (Round to four decimal places as needed.)