Hi, I'm having trouble figuring out how to solve this homework problem. I understand how to find the z-score, but I do not know how to find out what the other values are and how many of the other values there are.
"Suppose you have a normal distribution with a mean of 10 and a standard deviation of 5. You sample one person from the distribution and find they have a value of 8. What is the z-score for this subject?"

You will need to know the formula:

z = \frac{x - \mu}{\sigma}

Where x is the value,
mu is the mean
sigma is the standard deviation