Question

The mean for your data set is 13. The standard deviation is 2.5. What is the z-score for 10? Note 1: If necessary, round your answer to 3 decimal places

Answer 1

Z-score is given by the formula:
z=(x-μ)/σ
where:
μ-mean
σ-standard deviation
thus the z-score for the data set with mean 13 and standard deviation of 2.5 will be:
z=(10-13)/2.5
z=-1.2