Hopefully this will enable you to find the answer after doing a bit of arithmetic
http://wpage.unina.it/fabrnico/DIDAT...-Propeller.pdf
an extract from Dr John Lowry’s book mentioned here (they removed the charts so see the book)
https://www.avweb.com/features_old/t...ler-airplanes/
correct term is total activity factor (blade activity factor multiplied by the number of blades) rather than solidity
(I wonder what their source document for their question was)