15 The exam score among the college students in a particular

15

The exam score among the college students in a particular country are normally distributed with a mean of 500 and a standard deviation of 100. What is the probability that a randomly selected individual from this population has a score at or below 600?

Solution

We first get the z score for the critical value. As z = (x - u) / s, then as          
          
x = critical value =    600      
u = mean =    500      
          
s = standard deviation =    100      
          
Thus,          
          
z = (x - u) / s =    1      
          
Thus, using a table/technology, the left tailed area of this is          
          
P(z <   1   ) =    0.841344746 [ANSWER]