A large retirement community wants to host a grand birthday party for its residents who recently
became centenarians (a centenarian is someone who has lived 100 years). The party organizers learn
that 25 new centenarians will be the guests of honor at the party, so they decide to prepare some
interesting facts about this group's age. They start brainstorming, and one of the organizers says,
"Hey, the standard deviation of their ages would be an interesting fact."
Which of the following best represents the standard deviation for the ages of the new centenarians?