Question

in the data set below, what is the lower quartile? 21 31 55 62 62

Explanation:

Step1: Arrange data in order

21, 31, 55, 62, 62

Step2: Calculate position of lower - quartile

$n = 5$, position of lower - quartile $= \frac{n + 1}{4}=\frac{5+1}{4}=1.5$

Step3: Find lower - quartile

The lower - quartile is between 21 and 31. Using linear interpolation: $21+(31 - 21)\times0.5=21 + 5=26$

Answer:

26