
We could really group this data any way we want. In fact, we could only have two

rows, one for the number of students younger than 50 years old, and one for the

number greater, but we don't have to. We could even have one row for each age.

So here, we could have 10, 11, 12, and then we would count to see how many

students are aged 10, how many students are aged 11. But this is not the most

convenient way. That's because, the frequency would most likely be 1 for all of

them, maybe 2 for a few. So, instead of doing that, how about we choose an

interval for each row? For example, 0 to 19 and then 20 to 39, then we can count

how many students are between ages 0 and 19, between 20 and 39, etc. This is

called the interval or bin or bucket. For the most part, we'll either call it an

interval or the bin and in this case the bin size is 20. That's because it

includes 0.