Statistics-wise, it’s a another story when you pull in all ages and the world’s population.
Stephenson said a child having a “golden birthday” — turning the same age on the same day of the month — happens regularly. Add the year into the mix and it makes it a once-in-a-lifetime event for some people, while others will never see it.
For fifth-graders, assuming a reasonably uniform population, “approximately one out of 365 of them will turn 11 on that date,” Stephenson said.
Jacob Wheeler just happens to be one of those kids.
The son of Tracy Wheeler and Shawn Toth of Grand Haven, and a student at Ferry Elementary School, Jacob is really excited about this birthday, said Toth.
“I think my ‘golden birthday’ is awesome because not everyone gets to have one,” Jacob wrote in a letter to the Tribune. “It’s a once-in-a-lifetime opportunity.”
Jacob — who likes football, soccer and hockey — said he would love to have a surprise party for his birthday.
“He’s a really good kid, really smart,” Toth said. And his 8-year-old sister, Hailee, “is pretty excited for him.”
Katie Pease, the daughter of Mark and Heather Pease of Grand Haven Township, is another local child turning 11 on Nov. 11.
“She’s excited in a different way this year,” said her mother.
The fifth-grader at Peach Plains Elementary School also realizes her birthday this year is a unique event, Heather said. She said Katie usually celebrates her birthday with family or has a couple of friends over.
“This year, she wanted to invite all the girls in her class,” her mother said.
To read more of this story, see today’s print or e-edition of the Grand Haven Tribune.
Odds of turning 11 on 11/11/11
Paul Stephenson, professor and chairman of the Grand Valley State University Department of Statistics, provided the following observations about the odds of turning 11 on Nov. 11, 2011:
— There are 12 such instances of this type of occurrence: turning 1 on 1/1/01, turning 2 on 2/2/02, and up to turning 12 on 12/12/12. You can call each of these “special birthdays,”
— Everyone who has the opportunity of having this type of special birthday was born in 2000. Further, if you were born in 2000 (a leap year), the probability of getting to celebrate one of these special birthdays is 12/366. Note: This probability estimate assumes that birth on any given day is equally likely.
— Using U.S. birth data over the past 100 years, the probability of having one of these special birthdays is approximately 0.0004. In other words, approximately one in 2,500 babies born in the past 100 years in the U.S. will celebrate one of these special birthdays.
— Only one of the 12 special birthdays is turning 11 on 11/11/11. Therefore, approximately one in 30,000 babies born in the past 100 years in the U.S. will turn 11 on 11/11/11.