How can I calculate the median of sales price using 3 variables in Tableau

Question

Data

Type             Borough       ListPrice
RentalType1      Manhattan       $5,000
RentalType2      Bronx           $3,000
RentalType2      Brooklyn        $3,000
SalesType2       Manhattan       $900,000
SalesType1       Brooklyn        $100,000
SalesType1       Bronx           $500,000
SalesType2       Queens          $800,000
SalesType2       Staten Island   $400,000

What I actually want.

I want to calculate the median of sales price and the median rental price for an apartment in NYC( each of the 5 boroughs, Brooklyn, Bronx Manhattan, Queens and Staten Island).

In Tableau the sales and and rentals are groups of ListPrice -- Variables ListPrice is NUMBER(decimal) Type (includes Sales & Rentals, Borough

Any help is appreciated

What I already tried?

I tried creating a calculated field but I guess that somehow did not worked for me. Following is what I tried in the calculated :

WINDOW_MEDIAN(SUM([ListPrice])-1, -1)  

ERROR: WINDOW_MEDIAN is being called with (float, integer), did mean 
(float,integer,integer) 

Answer 1

First let me clarify things for you. Your table calculation takes 3 arguments: Expression, First row and last row of the partition and what you did that, in your formula you haven't given last row of the partition.

You must run the function for type in each Borough and then calculate for each Borough.

So this is how your formula should look like:

WINDOW_MEDIAN(SUM(INT([List Price])),FIRST(),LAST())

Here calculation2 is median value