Start and end balance per month

Question

Hello,
I am new in building formulas.
I have the following values in in my table, I would like to find out the start and end balance for month Jan and Feb.
Table: Transactions
Date
Balance
02/Jan/2014
100
05/Jan/2014
150
25/Jan/2014
120
09/Feb/2014
180
14/Feb/2014
200
16/Feb/2014
100
22/Feb/2014
190
Table: Results
Jan
Feb
Start balance
100
180
End balance
120
190
Can you please help with the simplest formula to get the above result?
I don't know when the first and last transaction will occur in a certain month. Also I don't know the total number of transactions per month.

Answer 1

I would like to find out the start and end balance for month Jan and Feb.
Assuming you are looking for the starting and ending balance for each month, and not the maximum and minimum balance, then you could do something like this:
Add an Index column to your Transactions table that extracts the month name with this formula in C2, copied down:
   =MONTHNAME(MONTH(A2))
(I first had to change the format of the dates in column A so Numbers would recognize them as dates on my machine.
In the results table I made sure I entered January and February as text, by typing an apostrophe (single quote) and typing the month name.  Otherwise Numbers smart date recognition will try to turn the month name into a date. (Note I used the full month name rather than an abbreviation.)
The formula in B2 of the Results table, copied to C2, is:
    =INDEX(Transactons::$B,MATCH(B$1,Transactons::$C,0))
The formula in B3 of the Results table, copied to C3, is :
     =INDEX(Transactons::$B,MATCH(B$1,Transactons::$C,1))
The INDEX MATCH combination is a flexible alternative to the LOOKUP, VLOOKUP family of functions. Here changing the last parameter in MATCH does the trick for finding the start and end balance.
SG