Question

Suppose years of education is approximately normally distributed with µ=17 years and σ=1.5 years. What is the probability of randomly selecting a student with a college degree from this population (college=20 years or more)? (Provide 3 decimal places in your answer)

Answer 1

Solution :

Given that ,

mean = = 17

standard deviation = = 1.5

P(x 20) = 1 - P(x   20)

= 1 - P[(x - ) / (20 - 17) / 1.5]

= 1 -  P(z 2)   

= 1 - 0.9772

= 0.023

probability = 0.023