# Interest Rate Help

• Jun 9th 2011, 05:14 PM
testing12
Interest Rate Help
Hello Everyone,

Can someone please tell me if the following is correct?

http://img708.imageshack.us/img708/7327/unledqsj.jpg
• Jun 9th 2011, 07:37 PM
TKHunny
I'm a little troubled why you bothered to turn the values into percents. What would you do if it was $150,000 and there was another$50,000 @ 15%?
• Jun 11th 2011, 03:58 AM
testing12
Hi there,

It happened to be convenient since the total was 100 k.
Can someone confirm if the final answer is correct?
• Jun 11th 2011, 05:23 AM
SpringFan25
i haven't checked your arithmatic but the sum you wrote down will give the right answer. (but only in this case as TKhunny pointed out)
• Jun 11th 2011, 08:41 AM
testing12
thank you sir.
• Jun 11th 2011, 09:47 AM
TKHunny
I just have to struggle with this. Which part did you do incorrectly on purpose! A very. very large part of success is personal confidence. Learn the facts. Execute a rational algorithm. Know what you are doing on each step along the way. Check you work. Move on. (You may wish to pay up you E&O Insurance)

More generally: $\frac{30(0.30) + 20(0.25) + 50(0.20)}{30 + 20 + 50}$

The percentages can take care of themselves.