On average do sperm live more in the 24-72 hour range or is it really common for sperm to live 5-7 days?

Depends where they R: Sperm can survive up to 5 - 7 days in woman's fallopian tube. Can survive a number of days exposed to vaginal or cervical secretions provided acidity of secretions is within a range suitable for sperm survival & nutrition. Sperm outside the body are dead as soon as semen has dried off. Sperm die very rapidly if released into water such as bath or swimming pool.