Solved: Calculator Issues? Annuity Value at 6 Years w/ 6.8% Compounded Annually

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Homework Help Overview

The discussion revolves around calculating the future value of an annuity with a fixed annual contribution of $3000 at an interest rate of 6.8% compounded annually over six years. Participants are examining the application of the annuity formula and the accuracy of their calculations using a web-based calculator.

Discussion Character

  • Mathematical reasoning, Problem interpretation, Assumption checking

Approaches and Questions Raised

  • Participants explore the correct application of the annuity formula and discuss potential errors in their calculations, particularly focusing on the placement of parentheses in the formula. There are attempts to clarify the structure of the formula as it is input into a calculator.

Discussion Status

Some participants have identified specific errors in their calculations related to the use of parentheses, while others are questioning the necessity of including certain operations, such as division and multiplication by 1. The discussion reflects a mix of realizations about calculation errors and suggestions for simplifying expressions.

Contextual Notes

Participants express frustration over the initial lack of responses and the challenges faced without access to a scientific calculator. There is an emphasis on the importance of careful debugging and understanding the mathematical expressions being used.

yumito
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Homework Statement


To save money you put $3000 at the end of each year in an annuity that pays 6.8% compounded annually. Use the formula for the value of an annuity.
The Given Formula:
Code:
A=P[(1+(r/n)[SUP]nt[/SUP])-1]
     ______________
           (r/n)
How much would be saved at the end of six years.

Homework Equations


The Variables:
Code:
P=3000
R=.068
n=1
t=6
The Completed formula:
Code:
A=3000((1+(.068/1)^(1)(6))-1)
     _______________________
           (.068/1)
When i put this exactly into http://web2.0calc.com/ (because I am without a scientific calculator at the moment)

The Attempt at a Solution



My Final Answer Is: A=44102.945538271292235294118
Rounded To The Nearest dollar: A=$44103
The program I Am Submitting The Answer To Says, the answer is: A=$21352 rounded to the nearest dollar.

My question is why is my answer wrong, is it the calculator? do i have a parentheses out of place?


_____________________________________________________________________________
EDIT: fixed spelling errors and a few minor changes, none involving the math.
 
Last edited:
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after about an hour of crying and an hour of raging that no1 would reply i figured out the mistake it was a parentheses
 
So it was the missing parents around the (1)(6) factor right?
 
nope, it wasn't, even tho that would have been another issue if my post was completely honest i actually multiplied them together before i put it in the calculator, the issue was the (1+(.068/1)^(1)(6)) should have been ((1+(.068/1))^((1)(6)))
 
in other words, add the 1 to the fraction before the exponent
 
yumito said:
...the issue was the (1+(.068/1)^(1)(6))
should have been ((1+(.068/1))^((1)(6)))


What I do to reduce the number of parentheses for that part in the
calculator display and make it relatively easier to read is type:


((1+0.068/1)^(1*6))
 
well from my time spend in my programing classes i must have completely forgotten how to debug, i have become too reliant of others help and need to seriously look at the problem before asking for help. on the most basic level, there are more just remove the outter most set of parenthesis until you see the problem lol
 
checkitagain said:
What I do to reduce the number of parentheses for that part in the
calculator display and make it relatively easier to read is type:


((1+0.068/1)^(1*6))

Why do you show division by 1 and multiplication by 1? Instead of 1 + .068/1, why not write 1.068? And instead of 1*6, why not write just 6?
 
Mark44 said:
Why do you show division by 1 and multiplication by 1?
Instead of 1 + .068/1, why not write 1.068?
And instead of 1*6, why not write just 6?

I was emphasizing an intermediate step where it is common for some beginning
calculator users to enter a product incorrectly. I was allowing for a denominator
other than 1 and a larger product for the exponent by my example.**

For myself, I would actually enter it they way you asked about for
[i[that problem[/i], because I know that is even simpler and I can
do that in my head.



** Example:

P(1 + 0.068/12)^(12*17) is what I would type for a different example
with relatively more difficult arithmetic.
 

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