.4 and .40 are indeed the same amount.
We usually drop the 0 in the 100'ths place when it is not necessary for indicating money or solving a problem with 2 decimals.
Also realize that .400 .4000 etc are all the same as well.
Here is what your frequency/cumulative frequency table would look like. The cumulative frequency is where you add all the frequencies from before it to get a sum after each interval.
<u> Frequency </u> <u>Cumulative Frequency</u>
0-25 8 8
26-50 0 8
51-75 4 12
76-100 2 14
5/4 x 22/45
110/ 180
11/18