Answer: medium 18. Range 6 ,25th percentile 17 , 75th percentile 20 ,IQR 3
Step-by-step explanation from the given figure, median is equal to 18, the range is equal to 21-15 equal to 6. The 25th percentile is equal to17 while the 75th is equal to 20. IQR then is equal to 20-17 equal to 3.