In: Statistics and Probability
The average GPA at a college is 2.73 with a standard deviation of 0.8. Find the probability that 10 randomly selected students will have an average GPA greater than 2.37
Solution :
Given that ,
mean = 
 = 2.73
standard deviation = 
 = 0.8
n = 10

= 2.73

= 
 / 
n = 0.8 / 
10 = 0.2530
P(
 >2.37 ) = 1 - P(
<2.37 )
= 1 - P[(
- 
) / 
< (2.37 -2.73) /0.2530 ]
= 1 - P(z < -1.42)
Using z table
= 1 - 0.0778
= 0.9222
probability= 0.9222