Answer: Interquartile range is 4.75.
Step-by-step explanation:
Given : Data set {48, 50, 65, 60, 80, 42, 45, 50, 42, 55, 45}.
To find : What is the interquartile range of the data set?
Solution : We have Data set {12 ,14, 16, 17.5 ,10 ,18, 15, 15.5 ,19 }.
Order the number:
10, 12, 14, 15, 15.5, 16, 17.5, 18, 19.
Median : (10, 12, 14, 15,) 15.5,( 16, 17.5, 18, 19).
15.5 is the median .
Median of first quartile Q1 : =13
Median of second quartile Q2 : =17.75.
Interquartile range = Q2-Q1 = 17.75 - 13 = 4.75.
Therefore, Interquartile range is 4.75.