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. What percentage of customers require less than 32 minutes for a simple haircut?
A)95.99 percent
B)99.45 percent
C)97.72 percent
D)45.99 percent Using Excel =NORMDIST(32,25,4,1) = 0.9599, or use z = (32 - 25)/4 = 1.75 with AppendixC.

Question

Quizplus · Accepted Answer

Using the Z-score formula, $Z = \frac{(X - \mu)}{\sigma}$, where $X = 32$, $\mu = 25$, and $\sigma = 4$, we get $Z = \frac{(32 - 25)}{4} = 1.75$. Looking up 1.75 in the Z-table or using Excel's NORM.DIST function gives us approximately 0.9599 or 95.99%.

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