Question

It has been determined that the mean amount of time that computer science majors spend on homework each week is approximately normally distributed with a mean of 15.2 hours and standard deviation 3.1 hours. What is the probability that a randomly selected computer science major will spend more than 14.5 hours on homework in a given week?

Answer 1

Solution:

Given that,

mean =  = 15.2 hours

standard deviation =  = 3.1 hours

p ( x > 14.5 )

= 1 - p (x < 14.5)

= 1 - p ( x -  / ) < ( 14.5 - 15.2/ 3.1 )

= 1 - p ( z < - 0.7 / 3.1 )

= 1 - p ( z < - 0.23 )

Using z table

= 1 - 0.4090

= 0.5910

Probability = 0.5910