Question

here are the travel times in minutes for 15 workers in north carolina, chosen at random by the census bureau, along with a dotplot of the data. 30 20 10 40 25 20 10 60 15 40 5 30 12 10 10 find the interquartile range of the distribution. iqr = minutes (enter an integer.)

Explanation:

Step1: Sort the data

$5, 10, 10, 10, 10, 10, 12, 15, 20, 20, 25, 30, 30, 40, 40, 60$

Step2: Find the median (Q2)

Since $n = 15$ (odd), the median is the 8 - th value. So $Q2=15$.

Step3: Find the lower half

The lower half is $5, 10, 10, 10, 10, 10, 12$. The median of the lower half (Q1) is the 4 - th value, so $Q1 = 10$.

Step4: Find the upper half

The upper half is $20, 20, 25, 30, 30, 40, 40, 60$. The median of the upper half (Q3) is the 4 - th value of the upper - half data set, so $Q3=30$.

Step5: Calculate the inter - quartile range

$IQR=Q3 - Q1=30 - 10 = 20$.

Answer:

$20$