I can't seem to figure out the class interval for this grouped frequency distribution table:

Highest Score=684
Lowest Score=56

& the professor has instructed us to use an interval size of 61

The starting point needs to be divisible by 61 due to convention.

But the lowest score 56 is not divisible by 61. Help!

1 answer

How about starting at zero score and having 13 intervals?:
0-61
62-123
124-185
etc.
620-681
682-743