Final answer:
The mean (µ) and the standard deviation (σ) need to be present to determine the z-score.
Step-by-step explanation:
The two things that need to be present to determine the z-score are the mean (µ) and the standard deviation (σ). The z-score is a measure of how many standard deviations an individual data point is from the mean of a distribution. It is calculated using the formula:
z = (x - µ) / σ
where x is the data point, µ is the mean, and σ is the standard deviation.