Homework SourseX75 Sx 10 n600 How many students scored 80 and above X75 Sx
X=75
Sx= 10
n=600
How many students scored 80 and above? X=75
Sx= 10
n=600
How many students scored 80 and above? X=75
Sx= 10
n=600
Solution
X follows normal with mean = 75 and standard deviation =10
Z-score of 80 =(80-75)/10 = 5/10 = 0.5
P( X >= 80) = P( Z >= 0.5) where Z follows standard normal distribution
= 1 - 0.6915
= 0.3085
Number of students scored 80 and above = 600 * 0.3085 = 185( approximately)
