The typical college freshman spends an average of $\mu$ = 150 minutes per day, with a standard deviation of$\sigma$ = 50 minutes, on social media. The distribution of time on social media is known to be Normal. The third quartile is:
A)183.72 minutes.
B)0.25 minutes.
C)116.27 minutes.
D)0.75 minutes.

Question

Quizplus · Accepted Answer

The third quartile is the 75th percentile which can be found using the Z-score formula:
Z = (x - μ)/σ 
where x is the value at the 75th percentile, μ is the mean, and σ is the standard deviation.
Using the values given, we have:
Z = (x - 150) / 50
From a standard Normal distribution table, the Z-score for the 75th percentile is approximately 0.674.
Therefore, 0.674 = (x - 150) / 50
Solving for x, we get:
x = 0.674 * 50 + 150 = 183.72
So the answer is A) 183.72 minutes.

The Typical College Freshman Spends an Average Of μ\muμ = 150 Minutes Per Day, with a Standard Deviation Of 150

The Typical College Freshman Spends an Average Of $\mu$ = 150 Minutes Per Day, with a Standard Deviation Of 150