Answer: 19.
Explanation:
1: Place your numbers in numerical order from smallest to largest; 15,19,20,25,31,38,41.
2. Find your median in the set of numbers; 15,19,20,25,31,38,41.
3. Find Q1 and Q3 in your set of numbers by placing parentheses around the median you have just found. (15,19,20),25,(31,38,41.)
4. In this instance, you need to find the medians of the two number sets in parentheses; (15,19,20), 19 being Q1, and (31,38,41), 38 being Q3.
5. Using the interquartile range formula; Q3-Q1= IQR, plug in your numbers.
38-19=19, making the answer 19.