I am wondering how to solve questions like this one:
There are a group of men are of heights which are normally distributed with μ = 173 cm and σ = 20 cm. A random sample of 300 men is chosen.
What is the probability that the arithmetic mean is greater than 171 cm?
I am not familiar with how exactly to solve questions like these. I assume I need to use statistical tables as the final step to get the probability, but I don't know what to do before that. Am I supposed to calculate a z-value?