Question

what is the measure of quartile 1 for this data? a. 24 b. 27 c. 28 24, 27, 28, 30, 31, 25, 21, 33, 28, 20, 27

Explanation:

Step1: Arrange data in ascending order

20, 21, 24, 25, 27, 27, 28, 28, 30, 31, 33

Step2: Calculate position of Q1

The formula for the position of the first - quartile ($Q_1$) for a data set of size $n$ is $i=\frac{n + 1}{4}$. Here, $n = 11$, so $i=\frac{11+1}{4}=3$.

Step3: Find Q1 value

Since $i = 3$ is an integer, the first - quartile $Q_1$ is the 3rd value in the ordered data set. So $Q_1=24$.

Answer:

A. 24