Question

The quality grade point average gpa of 200level economics student follows approximately a normal distribution with mean of 3.4 and SE of 2.2.How many of these students would expect to have a score between 3.5 and 4.5 inclusive,if the grade point average are computed to the nearest tenth

Answer 1

$\mu=3.4, \sigma=2.2, n=200,$

$P(3.5≤x≤4.5)=P(\frac{3.5-3.4}{2.2}≤Z\leq \frac{4.5-3.4}{2.2})$

$=P(0.05≤Z≤0.5)=P(Z≤0.5)-P(Z≤0.05)$

$=0.6915-0.5160=0.1755$ ,

$0.1755*200=35.1$