If a random variable X is normally distributed with mean μ = 0.45 and standard deviation σ = 0.40, then what is P(X ≥ 0.75)?
A) 0.7500
B) 0.7734
C) 0.2266
D) 0.2734

Question

Quizplus · Accepted Answer

To find P(X ≥ 0.75), we need to standardize the variable x. 
z = (x - μ) / σ
z = (0.75 - 0.45) / 0.40 = 0.75
Using the standard normal distribution table, the probability of z being greater than or equal to 0.75 is 0.2266. Therefore, P(X ≥ 0.75) = 0.2266.

If a Random Variable X Is Normally Distributed with Mean