In Melanie's Styling Salon,the time to complete a simple haircut is normally distributed with a mean of 25 minutes and a standard deviation of 4 minutes.The slowest quartile of customers will require more than how many minutes for a simple haircut?
A)3(n + 1)/4 minutes
B)26 minutes
C)25.7 minutes
D)27.7 minutes

Question

Quizplus · Accepted Answer

To find the slowest quartile, we need to find the 75th percentile of the distribution. Using a standard normal table or calculator, we can find the z-score corresponding to the 75th percentile as 0.674. We can then use the formula z = (x - μ) / σ to find the corresponding value of x (the haircut time). Solving for x, we get:
0.674 = (x - 25) / 4
x - 25 = 2.696
x = 27.696
Rounding up to the nearest minute, we get 28 minutes as the answer. Therefore, the slowest quartile of customers will require more than 27.7 minutes for a simple haircut.

In Melanie's Styling Salon,the Time to Complete a Simple Haircut