A normal distribution has a mean of 120 and a standard deviation of 10. Find the z-score for a data value of 87.
To find the z-score for a data value, you use the formula:
z = (x - μ) / σ
where:
z is the z-score
x is the data value
μ is the mean
σ is the standard deviation
In this case, x (the data value) is 87, the mean (μ) is 120, and the standard deviation (σ) is 10.
Plugging these values into the formula, we get:
z = (87 - 120) / 10
z = -33 / 10
z = -3.3
Therefore, the z-score for a data value of 87 is -3.3.