The annual salaries of all employees at a financial company are normally distributed with a mean mc014-1.jpg = $34,000 and a standard deviation mc014-2.jpg = $4,000. what is the z-score of a company employee who makes an annual salary of $28,000?

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

The right answer is option d.