Originally Posted by
tester85 I have a simple stats problem where the following table is given.
Speed (Km/h)--------Frequency-----------Cumulative Frequency
0<s<=40--------------14----------------------14
40<s<=60-------------51----------------------65
60<s<=70-------------157---------------------222
70<s<=80-------------141---------------------363
80<s<=100------------37----------------------400
I am asked to find the median which i can find easily 51, but the standard deviation i tried all sorts of values but unable to get the given answer which is 64.6. I am getting like 13.67. Can someone guide me out on this issue ?