Answer:
The probability that a randomly selected graduate will have a starting salary of $50,000 or more is 10.56%
Step-by-step explanation:
The formula for calculating a z-score is:
Z=
![(x-μ)/(σ)](https://img.qammunity.org/2020/formulas/business/college/11qspcf69rei4dopv3b1d44nw0pwwaw5ie.png)
Where:
x=Score in this case is $50,000
μ=Mean or average of the salary: $45,000
σ= standard deviation of $4,000.
Z=
![(50000-45000)/(4000)](https://img.qammunity.org/2020/formulas/business/college/wcpv99zm10ytup4ziuqk0xz87kqop7s0vd.png)
Z= 1.25
This value has an associated probability of 0.8944= 89.44%, this means 89.44% of graduates will have a starting salary of $50,000 or less.
But if we want to know the probability that the graduate has a salary of $50,000 or more, taking into account a population of 100%=1
1-0.8944= 0.1056
Which represents that 10.56% of population of graduates will earn $50,000 or more.