Hello, I need help with this question: If a researcher takes on sample of size 4 (n=4) from this population, what is the probability that he or she computes a sample mean of at least 23 (M=23) minutes? Note: You must compute the z-transformation for sampling distributions, and then refer to the unit normal table to find the answer.

Other information prior that might be helpful is: The research cites that attention span (time in minutes attending to some task) in the population is normally distributed with the following characteristics: 20 +- 36. Population mean of 20, population variance computed of 6