i need help on determining if their is an outlier...i know how to find the median and the lower quartile and the upper quartile..but i don't understand about the outliers....please tell me if their is an outlier in this problem....the numbers are...63,88,89,89,95,98,99,99,100,100
You have 10 data points and hence from the bottom 5 you get a lower quartile of Q1 = 89 and an upper quartile of Q3 = 99. Hence the box extends from 89 to 99 and the interquartile range IQR is 99 - 89 = 10.
An outlier is any data point that is more than 1.5 times the IQR from either end of the box. 1.5 times the IQR is 1.5 10 = 15 so, at the upper end an outlier is any data point more than 99 + 15 = 114. There are no data points larger than 114 so there are no outliers at the upper end.
At the lower end an outlier is any data point less than 89 - 15 = 74. There is one data point, 63, which is less than 74 so 63 is an outlier.
I hope this helps.