Respuesta :
The z-score of a certain data is calculated through the equation,
z-score = (x - μ) / σ
where x is the data, μ is the mean and σ is the standard deviation.
Substituting,
z-score = (28,000 - 34,000) / 4,000
z-score = -1.5
z-score = (x - μ) / σ
where x is the data, μ is the mean and σ is the standard deviation.
Substituting,
z-score = (28,000 - 34,000) / 4,000
z-score = -1.5