A statistician
A person who studies Fleas.
Stamp Dealer. A philatelist is someone who studies stamps.
Differential statistics are statistics that use calculus. Normally statistics would use algebra but differential statistics uses calculus instead of algebra.
Old
A statistician
A scientist who studies the growth and density of populations and their vital statistics is known as a demographist!
demographist
A sabremetrician is a person who studies sabremetrics - intricate baseball statistics.
How about "statistician"? But I admit that the spelling is a challenge to get right !
A person who studies genealogies is a genealogist.
A person who studies philosophy is called a philosopher.
A person who studies organisms is called a biologist.
a person who studies people but not an psychologist
a person that studies gems is called a gemologist.
A person who is professionally qualified to work with statistics is a 'statitician'. (STAT-iss-TISH-un)
what do you call somebody who studies snails.