Intervals Frequency Cumulative% 26-30 2 6.89% 31-35 1 3.44% 36-40 1 3.44% 41-45 3 10.34% 46-50 0 0.00% 51-55 5 17.24% 56-60 7 24.13% 61-65 5 17.24% 66-70 0 0.00% 71-75 2 6.89% 76-80 3 10.34% Please find the Semi-interquartile range (2 pts) Solution The semi-interquartile range is a measure ofspreadordispersion.It is computed as one half the difference between the 75thpercentile[often called (Q3)] and the 25th percentile (Q1). The formula for semi-interquartile range is therefore: (Q3-Q1)/2. You have 11 samples. Q1 occurs at 25% of 11 = 2.27 So you average the 2nd and 3rd sample. =1 3.44% Q3 occurs at 75% of 11 = 8.25 . So you average the 8th and 9th sample = 2.5 8.62% Semi interquartile range=0.75 2.59 %.