Questions: The year Teresa graduated college, the starting salaries of all entry-level software engineers in the United States had a mean of 92,000 and a standard deviation of 1080. That year, Teresa got a job as an entry-level software engineer working for a firm in the United States. Her starting salary was 89,000.
(a) Find the z-score of Teresa's starting salary relative to the starting salaries among all the entry-level software engineers in the United States for the year Teresa graduated. Round your answer to two decimal places.
[
z=square
]
(b) Fill in the blanks to interpret the z-score of Teresa's starting salary. Make sure to express your answer in terms of a positive number of standard deviations.
Teresa's starting salary was standard deviations (Choose one) V the mean starting salary of all entry-level software engineers in the United States.
Transcript text: The year Teresa graduated college, the starting salaries of all entry-level software engineers in the United States had a mean of $\$ 92,000$ and a standard deviation of $\$ 1080$. That year, Teresa got a job as an entry-level software engineer working for a firm in the United States. Her starting salary was $\$ 89,000$.
(a) Find the $z$-score of Teresa's starting salary relative to the starting salaries among all the entry-level software engineers in the United States for the year Teresa graduated. Round your answer to two decimal places.
\[
z=\square
\]
(b) Fill in the blanks to interpret the $z$-score of Teresa's starting salary. Make sure to express your answer in terms of a positive number of standard deviations.
Teresa's starting salary was standard deviations (Choose one) $\mathbf{V}$ the mean starting salary of all entrylevel software engineers in the United States.
Solution
Solution Steps
To find the z-score of Teresa's starting salary, we use the formula for the z-score: z=σX−μ, where X is Teresa's salary, μ is the mean salary, and σ is the standard deviation. For part (b), interpret the z-score by determining how many standard deviations Teresa's salary is from the mean and whether it is above or below the mean.
Step 1: Calculate the z-score
To find the z-score of Teresa's starting salary, we use the formula:
z=σX−μ
where:
X=89000 (Teresa's salary),
μ=92000 (mean salary),
σ=1080 (standard deviation).
Substituting the values, we get:
z=108089000−92000=1080−3000≈−2.778
Step 2: Interpret the z-score
The z-score of −2.778 indicates that Teresa's starting salary is approximately 2.778 standard deviations below the mean starting salary of all entry-level software engineers in the United States.
Final Answer
(a) The z-score of Teresa's starting salary is −2.78.
(b) Teresa's starting salary was 2.78 standard deviations below the mean starting salary of all entry-level software engineers in the United States.