I have checked the casio website but it is not very intuitive. Press 4STAT 1ON Change to Statistics Mode. Reading mean and standard deviation is the mean is the standard deviation Continue until you have entered all the frequencies Calculating mean and standard deviation Press CALC and SET You should see 1VAR XList List1 on the top line.
In this case the median is the 11 th number.
In Complex Mode operations can be carried out using the imaginary unit U. Its ok if there is more than one mode. You should see 1VAR Freq. DATA enters values into the data register.