premise: Ruth Pryor (1906-2001) was a Chicago ballet dancer and instructor, and the first American ballerina to dance the role of the Swan Queen in Swan Lake, in 1930. She was known for "her feat of whirling thirty-six times a minute on her toes," according to the Purple Parrot of Northwestern University.
hypothesis: Ruth Pryor lived to be around 95 years old.
reason: If Ruth Pryor was born in 1906 and passed away in 2001 then sh