A set of data has a mean of 127 and a standard deviation of 15. What is the z-score of x = 118?

The z-score is a measure of how statistically related a value is from the mean. It is a tool to standardize scores from different sets of data which is why it is also known as "Standard Score". It can be calculated using the formula:

z-score = (any value in the data - mean) : standard deviation

Given:

any value in the data = 118

standard deviation = 15

mean = 127

Solution:

z-score = (118 - 127) : 15

z-score = - 0.6