# Finding the possible values of a median

• May 13th 2011, 09:37 PM
IBstudent
Finding the possible values of a median
Hi,
I desperately need a method to find a median, without having to right all the values from small to large, , this method takes too much space and time, any good other method would be appreciated.
Thaknks
• May 13th 2011, 09:39 PM
IBstudent
please ignore the attachment, I can't find the option to delete it....
• May 14th 2011, 02:49 AM
Ackbeet
Probably one of the fastest algorithms is the quickselect algorithm, which is a generalization of finding the median (it can find what would be the kth element in the corresponding sorted list, except that the algorithm works on an unsorted list like you want). I don't know if this is what you were looking for. It's not that difficult to enter an unsorted list into Excel, ask Excel to sort the list, and then pick out the median that way.
• May 14th 2011, 05:27 AM
mr fantastic
Quote:

Originally Posted by IBstudent
Hi,
I desperately need a method to find a median, without having to right all the values from small to large, , this method takes too much space and time, any good other method would be appreciated.
Thaknks

Obviously you can use the given frequencies to count how much data there is and then determine which data value is in the middle (it will be the one that occurs at half the frequency). I suggest you review your class notes and textbook for an inevitable example.