Question

Teachers* Salaries The average annual salary for all teachers is $47,750. Assume that the distribution is normal and the standard deviation is $5680.Find the probabilities. P (42.000 ≤ X ≤ 58.500)

Answer 1

Remember that

z =(x - μ)/σ

In this problem

μ=47,750

σ=5,680

so

For x=42,000

z=(42,000-47,750)/5,680 --------------> z=-1.0123

For x=58,500

z=(58,500-47,750)/5,680 -----------> z=1.8926

using a z-scores table

we have that

P (42,000 ≤ X ≤ 58,500)=0.8151