Rainfall data calculation I have rainfall data, collected every 15 minute

TimeStamp         Rainfall (mm/hou)
26/10/2016 00:15:00         0
26/10/2016 00:30:00         0
26/10/2016 00:45:00         0
26/10/2016 01:00:00         0
26/10/2016 01:15:00         0
26/10/2016 01:30:00         0
26/10/2016 01:45:00         0
26/10/2016 02:00:00         0
26/10/2016 02:15:00         0
26/10/2016 02:30:00         0
26/10/2016 02:45:00         0
26/10/2016 03:00:00         0
26/10/2016 03:15:00         0
26/10/2016 03:30:00         0
26/10/2016 03:45:00         0
26/10/2016 04:00:00         0
26/10/2016 04:15:00         0
26/10/2016 04:30:00         0
26/10/2016 04:45:00         0
26/10/2016 05:00:00         0
26/10/2016 05:15:00         0
26/10/2016 05:30:00         0
26/10/2016 05:45:00         0
26/10/2016 06:00:00         0
26/10/2016 06:15:00         0
26/10/2016 06:30:00         0
26/10/2016 06:45:00         0
26/10/2016 07:00:00         0
26/10/2016 07:15:00         0
26/10/2016 07:30:00         0
26/10/2016 07:45:00         0
26/10/2016 08:00:00         0
26/10/2016 08:15:00         0
26/10/2016 08:30:00         0
26/10/2016 08:45:00         0
26/10/2016 09:00:00         0
26/10/2016 09:15:00         0
26/10/2016 09:30:00         0
26/10/2016 09:45:00         0
26/10/2016 10:00:00         0
26/10/2016 10:15:00         0
26/10/2016 10:30:00         0
26/10/2016 10:45:00         0
26/10/2016 11:00:00         0
26/10/2016 11:15:00         0
26/10/2016 11:30:00         0
26/10/2016 11:45:00         0
26/10/2016 12:00:00         0.29
26/10/2016 12:15:00         0.4
26/10/2016 12:30:00         0.4
26/10/2016 12:45:00         0.4
26/10/2016 13:00:00         0.54
26/10/2016 13:15:00         0.6
26/10/2016 13:30:00         0.6
26/10/2016 13:45:00         0.6
26/10/2016 14:00:00         0.3
26/10/2016 14:15:00         0.2
26/10/2016 14:30:00         0.2
26/10/2016 14:45:00         0.2
26/10/2016 15:00:00         0.05
26/10/2016 15:15:00         0
26/10/2016 15:30:00         0
26/10/2016 15:45:00         0
26/10/2016 16:00:00         0
26/10/2016 16:15:00         0
26/10/2016 16:30:00         0
26/10/2016 16:45:00         0
26/10/2016 17:00:00         0
26/10/2016 17:15:00         0
26/10/2016 17:30:00         0
26/10/2016 17:45:00         0
26/10/2016 18:00:00         0
26/10/2016 18:15:00         0
26/10/2016 18:30:00         0
26/10/2016 18:45:00         0
26/10/2016 19:00:00         0
26/10/2016 19:15:00         0
26/10/2016 19:30:00         0
26/10/2016 19:45:00         0
26/10/2016 20:00:00         0
26/10/2016 20:15:00         0
26/10/2016 20:30:00         0
26/10/2016 20:45:00         0
26/10/2016 21:00:00         0
26/10/2016 21:15:00         0
26/10/2016 21:30:00         0
26/10/2016 21:45:00         0
26/10/2016 22:00:00         0
26/10/2016 22:15:00         0
26/10/2016 22:30:00         0
26/10/2016 22:45:00         0
26/10/2016 23:00:00         0
26/10/2016 23:15:00         0
26/10/2016 23:30:00         0
26/10/2016 23:45:00         0
27/10/2016 00:00:00         0


I want the total amount of rain collected in the day ?

Am I right in doing the following?

1. Each reading multiplied by 15
2. Sum all the readings
3. Divide the sum by 24 


Will this give me the total amount of rain for the day? Thank you
Your readings are in mm/h.  Since $15$ minutes $= {1\over 4}$ hours, you should divide a reading by $4$ to get the total amount rain in mm that fell during that $15$ minute span.  Taking the sum of all readings and dividing by $4$ will thus give you the total rainfall for the day (in mm).  

This is assuming that the readings given are averages over the time span.  If they are instantaneous readings taken $15$ minutes apart, this can give you a decent estimate, but to obtain a better one you could use a more advanced numerical integration method instead (this method amounts to the rectangle rule).

For instance, using  Simpson's rule you would take $$\frac 1 {6} \sum_{i=1}^{12}(r_{2i-1}+2r_{2i})$$where $r_i$ is the $i^{th}$ reading.
Firstly ,add all the readings.Then multiply it with 1/4.It gives the amount of rain fall in mm.Then divide it by 24.It gives the amount of rain fall for the particular day i.e;mm/day