Hi!
So I included an image of a histogram I made, but here is another way to solve this.
Write all the numbers in order.
72, 78, 81, 86, 86, 87, 92, 92, 92, 98
Now, starting at 70, and with the interval length being 5, let's see how many bars there are.
72 | 78 | 81 | 86,86,87 | 92,92 | 98
70-75 | 76-80 | 81-85 | 86-90 | 91-95 | 96-100
BAR 1 BAR 2 BAR 3 BAR 4 BAR 5 BAR 6
Hopefully, that makes a little bit of sense. But I also included an image of an actual histogram.
The answer is 6 bars.
Hope this helps!
-Peredhel