The number of cell phone minutes used by high school seniors follows a normal distribution with a mean of 500 and a standard deviation of 50.What is the probability that a student uses more than 580 minutes?
A)0.152
B)0.0548
C)0.848
D)0.903

Question

Quizplus · Accepted Answer

We need to find the probability that a student uses more than 580 minutes, which is equivalent to finding the area to the right of 580 on the normal distribution curve.

Using the Z-score formula:

z = (x - μ) / σ

Where:

x = 580 (the value we are interested in) 
μ = 500 (mean) 
σ = 50 (standard deviation)

z = (580 - 500) / 50 = 1.6

We can now find the area to the right of z = 1.6 using a standard normal distribution table or a calculator.

Using a standard normal distribution table, we find that the area to the right of z = 1.6 is 0.0548.

Therefore, the probability that a student uses more than 580 minutes is 0.0548.

The Number of Cell Phone Minutes Used by High School