Get the functional of a PDF from PearsonDistribution

Questions
1

I am having trouble to get the functional form of the PDF using the PearsonDistribution method in Mathematica.
In my notebook, I use the following syntax -

fy = PearsonDistribution[-11.9287, 174.485, 0.0470701, -6.83086, -83.8092]
PDF[fy]

But the output I get is not in human readable syntax. Here is the output I get -
-----------Output-----------------

PearsonDistribution[1, -11.9287, 174.485, 0.0470701, -6.83086, \
-83.8092]

Function[\[FormalX], 
 If[-11.3772 < \[FormalX] < 156.498, 
  Exp[-LogGamma[1 + Statistics`PearsonDistributionsDump`t$8491[7]] - 
    LogGamma[1 + Statistics`PearsonDistributionsDump`t$8491[8]] + 
    LogGamma[
     2 + Statistics`PearsonDistributionsDump`t$8491[7] + 
      Statistics`PearsonDistributionsDump`t$8491[8]] + 
    Log[-\[FormalX] + 
       Statistics`PearsonDistributionsDump`t$8491[
        6]] Statistics`PearsonDistributionsDump`t$8491[7] + 
    Log[\[FormalX] + 
       1/2 Statistics`PearsonDistributionsDump`ib$8491 \
Statistics`PearsonDistributionsDump`t$8491[1] + 
       Statistics`PearsonDistributionsDump`t$8491[
        3]] Statistics`PearsonDistributionsDump`t$8491[8] + 
    Log[2] Statistics`PearsonDistributionsDump`t$8491[9] + 
    1/2 Log[Statistics`PearsonDistributionsDump`t$8491[
       2]] Statistics`PearsonDistributionsDump`t$8491[9]], 
  0], Listable]

I also attach the .nb file in the attachment.
Could you please suggest me how to get the functional form in human-readable format.

P.S. I use Mathematica 11.3 version.

Cheers,
Nirbhay

pdfandType.nb (31 KB)

2

Including Assumptions about the signs of the parameters seems to get a reasonable result:

pdf = Simplify[PDF[PearsonDistribution[a1, a0, b2, b1, b0], x],
    Assumptions -> {a0 > 0, b2 > 0, a1 < 0, b1 < 0, b0 < 0}] /.
   {a1 -> -11.9287, a0 -> 174.485, b2 -> 0.0470701, b1 -> -6.83086, b0 -> -83.8092} // PiecewiseExpand

piecewiseequation.png

Plot[pdf, {x, 0, 30}]

densityfunction.png
densityfunction.png796×434 6.4 KB