For the normal approximation to the binomial distribution with p = 1/2 and n = 100,what is the z-score corresponding to X = 60?
A)z = 0.4
B)z = 2.0
C)z = 0.2
D)z = 1.0

Question

For the normal approximation to the binomial distribution with p = 1/2 and n = 100,what is the z-score corresponding to X = 60?​
A)​z = 0.4
B)​z = 2.0
C)​z = 0.2
D)​z = 1.0

Quizplus · Accepted Answer

The mean of the normal approximation to the binomial distribution is μ = np = 100(1/2) = 50, and the standard deviation is σ = √np(1-p) = √(100*1/2*1/2) = 5. 
The z-score is calculated as z = (X-μ)/σ = (60-50)/5 = 2. Therefore, the correct choice is B.

For the Normal Approximation to the Binomial Distribution with P