I updated the average based on a much larger sample of Caucasians. Since there is ethnic variability with regards to 2D:4D ratio, that average ratio only applies to Caucasians and may not necessarily be generalized to other ethnicities.
Important quibble about racial invalidity. My ratio 2d:4d is 1.0 both hands. 86 mm. I have significant Native American ancestry, I look pretty odd with narrow short hands and feet, short arms and legs with a long back, hair on my head instead of my face or body, soft oily skin like Cher. I'm male.
I have wild mathmatical ability with a 1:10000 SAT score (verbal and mathematical one point apart) and a had a career in engineering. I also turned out to be really interested in music, and when given some piano lessons age 8, was pretty good at it. (For Art lessons I was undistinguished and swimming lessons I was a complete failure).
My Mother had enough mathematical ability, as a secretary she was a great tabular typist. She was not exposed to any algebra or geometry in school. They graduated her early to clear up the space for someone more important, there was a war going on. But at the end of her career as a secretary she transferred to computer programming, with no background mathematical training, only the specific Cobol training given by her employer. Mother was the person that found the Beethoven symphonies on the AM radio in 1934-43 by DXing, and bought the CRC classical kiddie records I enjoyed so much when I was 3 to 5. She bought the piano I learned on, but stopped taking lessons to move back to the mine with Dad.
Dad was an accountant, like his Father, He had very little interest in music. I don't think his parents had a radio until after he left home.
I'm a bit limited as a pianist because my hands do not fit the Russian/Prussian repretoire. JS Bach and Moussorgski could do things I can't do. But I can fake it pretty well, moving notes around sometimes to get rid of the twelths.