The scores on a psychology exam were normally distributed with a mean of 70 and a standard deviation of 9. What is the standard score for an exam score of 69?
To find the standard score, also known as the z-score, for an exam score of 69, we can use the formula:
z = (x - μ) / σ
where
x = the exam score
μ = the mean of the distribution
σ = the standard deviation of the distribution
Plugging in the given values:
x = 69
μ = 70
σ = 9
z = (69 - 70) / 9
z = (-1) / 9
z = -0.111
Therefore, the standard score for an exam score of 69 is approximately -0.111.