The Norwegian Forest cat is a large (big and strong) cat, a sturdy breed like the Maine Coon. Excluding instances of these feline lives cut short by heart and kidney disease, otherwise healthy adult cats for this breed live on average 15 years give or take 1 year; those lifespans for healthy adult Norwegian Forest cats can reasonably be estimated as normally distributed. Report any probabilities or percentages to the nearest hundredth with percent symbol, such as