My apologies if this comes out as stupid.
Problem (Domain : stock exchanges): I have been given the sum of orders placed per instrument(security or company) for about 25000+ instruments. So my dataset looks something like this:
[Instrument] [Order count] [Average Order Size(AOS)] [Orders above 10*AOS] AAA 20 10000.0 ? BBB 5000 24334.5 ? ...................
I know the average order size placed for an instrument as shown above. I want to calculate an estimate for the number of orders placed which had a order size above
10*[average order size] per instrument. I don't have an idea about the distribution. Assuming it's a normal distribution, I don't have an idea about the standard deviation. Is there any way to get a practical answer (I don't care if it is a value in a range.) for my problem? I hope this question is relevant here. Thanks.