Question

raquel recorded how long it took her to drive home from work 11 times. the number of minutes are listed below. 23, 20, 28, 31, 29, 24, 25, 26, 21, 18, 22. what is the interquartile range of the number of minutes? a. 6 b. 3 c. 24 d. 7

Explanation:

Step1: Sort the data

$18, 20, 21, 22, 23, 24, 25, 26, 28, 29, 31$

Step2: Find the median (Q2)

Since there are 11 data - points, the median is the 6th value. So, $Q2 = 24$.

Step3: Find the lower half

The lower half of the data is $18, 20, 21, 22, 23$. The median of the lower half (Q1) is the 3rd value, so $Q1 = 21$.

Step4: Find the upper half

The upper half of the data is $25, 26, 28, 29, 31$. The median of the upper half (Q3) is the 3rd value of this half, so $Q3 = 28$.

Step5: Calculate the inter - quartile range (IQR)

$IQR=Q3 - Q1=28 - 21 = 7$

Answer:

D. 7