Question

here are 13 of alis walk times to the nearest restroom (in seconds):
26, 34, 15, 62, 89, 71, 23, 13, 32, 54, 52, 50, 21
what is the first quartile?

Explanation:

Step1: Sort the data

Sort the walk - times in ascending order: \(13,15,21,23,26,32,34,50,52,54,62,71,89\)

Step2: Find the median of the lower half

Since \(n = 13\), the position of the first quartile \(Q_1\) is \(\frac{n + 1}{4}=\frac{13+1}{4}=3.5\)
The lower half of the data is \(13,15,21,23,26,32\)
The first quartile \(Q_1\) is the average of the 3rd and 4th values in the lower half.
\(Q_1=\frac{21 + 23}{2}\)
\(Q_1=\frac{44}{2}=22\)

Answer:

\(22\)