I have a model where I'm trying to calculate the accurate price for a
product every month. Unfortunately, I have a product where the price
increases by 3% every year in the middle of a month (for example:
March). I show the prices by month and March would have a blended
price but I can't come up with a formula to calculate the correct rate
for March? Any thoughts on how to write this...I am at a loss for a
simple solution. Below is the way the data should appear if the
formula is correct.

Price implemented: 3/16/2009
Annual Price Increase: 3%


Date Price
4/1/2009 $12.00
5/1/2009 $12.00
6/1/2009 $12.00
7/1/2009 $12.00
8/1/2009 $12.00
9/1/2009 $12.00
10/1/2009 $12.00
11/1/2009 $12.00
12/1/2009 $12.00
1/1/2010 $12.00
2/1/2010 $12.00
3/1/2010 $12.18
4/1/2010 $12.36
5/1/2010 $12.36
6/1/2010 $12.36
7/1/2010 $12.36
8/1/2010 $12.36
9/1/2010 $12.36
10/1/2010 $12.36
11/1/2010 $12.36
12/1/2010 $12.36
1/1/2011 $12.36
2/1/2011 $12.36
3/1/2011 $12.55
4/1/2011 $12.73

Thanks in advance for any help....AJ