The interquartile range can be found by first writing the elements in order from least to greatest.
28, 40, 43,43, 45, 50, 50 note there are 7 numbers in the list and it is easy to see that the median(the middle number is 43). The median separates the data in half... Now to find the IQR we need to find the difference of the third quartile and the first quartile.. the first quartile is just the median of the first half of the data. This would be 40.. The third quartile is just the median of the second half of the data. This would be 50. Now subtract 50 - 40 = 10 So the IQR is 10
