BI: Lessons Learned

Here is a little background on the above chart and some background on some of the things I had to think a bit about as I built.  Tableau Public Viz ·          Year Change ( o    FORMULA: FLOAT(LEFT([Year],4)) o    What it does; year was combined like this; 2018/2019 so the formulas took the last 4 digits of the year ·          Formula for Boys/Girls difference Since 2002 o    FORMULA ; (ZN(SUM([Girls Participation])) - LOOKUP(ZN(SUM([Girls Participation])), FIRST())) / ABS(LOOKUP(ZN(SUM([Girls Participation])), FIRST())) o    What it does; took the numbers and evaluated the comparison from 2003 to the next year always going back to 2003. o    Pieces of the formula ; §   ZN; ZN tests to see if a function is null, and if it is, it will return a value of zero §   Lookup; LOOKUP function that allows you to look up and down a partition of rows and return the value in that field by specifying an offset. In the formulas example, we are looking up the FIRST Value