If anybody can , i would really appreciate it!

To fill in the table, all you need to do is count. The first column shows the range or the intervals of the arm lengths. Count how many organisms there are with arm lengths that fall within the range. 

Look at the attached image of your worksheet. The color of the circles on the top corresponds with the number written on the table below. 

Now based on that, you can construct your table.

For the Number of organisms in year 1, look at the info in the Year 1 on the table above. The next columns follow the same pattern, for look at Year 50 for organisms in year 50, and look at Year 100 for organisms in year 100.  

Attached is a table that will show where the data came from.