Final answer:
The z-score of x = 4, which is 0.133 standard deviations to the left of the mean, is z = -0.133.
Step-by-step explanation:
The z-score is a measure that describes the position of a raw score in terms of its distance from the mean, measured by the standard deviation units. If a value x is 0.133 standard deviations to the left of the mean, it means that the value x is less than the mean, and so it has a negative z-score. As the x is only 0.133 standard deviations to the left, the z-score for x = 4 is z = -0.133.