![]() ![]() ![]() For each group of 23 or more birthdays that you collected, sort through them to see if there are any birthday matches in each group.Tip: Here are a few ways that you can find a number of randomly grouped people: Ask school teachers to pass a list around each of their classes to collect the birthdays for students in the class (most schools have around 25 students in a class) use the birthdays of players on major league baseball teams (this information can easily be found on the Internet) or use the birthdays of other random people using online sources.(You don't need the year for the birthdays, just the month and day.) Ideally you should get 10 to 12 groups of 23 or more people so you have enough different groups to compare. Collect birthdays for random groups of 23 or more people.Groups of 23 or more people (10 to 12 such groups) or a source with random birthdays (see Preparation below for tips).Consequently, each group of 23 people involves 253 comparisons, or 253 chances for matching birthdays. If you add up all possible comparisons ( 22 + 21 + 20 + 19 + … +1) the sum is 253 comparisons, or combinations. The third person then has 20 comparisons, the fourth person has 19 and so on. How much more? Well, the first person has 22 comparisons to make, but the second person was already compared to the first person, so there are only 21 comparisons to make. One is that when in a room with 22 other people, if a person compares his or her birthday with the birthdays of the other people it would make for only 22 comparisons-only 22 chances for people to share the same birthday.īut when all 23 birthdays are compared against each other, it makes for much more than 22 comparisons. ![]() Is this really true? There are multiple reasons why this seems like a paradox. The birthday paradox, also known as the birthday problem, states that in a random group of 23 people, there is about a 50 percent chance that two people have the same birthday. Don't believe it's true? You can test it and see mathematical probability in action! In this case, if you survey a random group of just 23 people there is actually about a 50–50 chance that two of them will have the same birthday. Have you ever noticed how sometimes what seems logical turns out to be proved false with a little math? For instance, how many people do you think it would take to survey, on average, to find two people who share the same birthday? Due to probability, sometimes an event is more likely to occur than we believe it to. ![]()
0 Comments
Leave a Reply. |