Questions having to do with financial mathematics. Please note that for questions in quantitative finance, quant.stackexchange.com is perhaps a better site.

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2
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0answers
187 views

numerical method (implicit , backward difference or forward difference) for nonlinear pde

$\newcommand{\lbar}{\underline{\lambda}}$ In this linear PDE: \begin{cases} B_t+b^Q(r,t)B_r+\frac{1}{2}d^2(r,t)B_{rr}+(\mu(\lambda,t)+\alpha \sigma (t))(\lambda -\lbar)B_{\lambda} \\ ...
2
votes
1answer
35 views

Understanding APR - can it be calculated as a dollar amount

If the APR (as used in the US Truth in Lending Act) is considered "the cost of your credit as a yearly rate," can an APR be converted to a dollar amount? For example 10% simple interest per year on a ...
2
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1answer
27 views

the relationship between fractional difference and ACF of a time sequence

When reading the GARCH modeling part of book Analysis of Financial Time Series, I read the following statement. In specific, I do not understand how does the author ...
2
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2answers
95 views

Understanding basic stochastic differential equations

This is from a physics course in economics, the literature provides a bare minimum of mathematical explanations. I am trying to understand how to work with stochastic differential equations given in ...
2
votes
1answer
27 views

Find APR with loan balance

Here is the problem: L: original loan amount B: current balance after P periods P: number of periods that have been paid A: period payment **you do not know the number of periods remaining, so ...
2
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0answers
126 views

Engineering Economics Cash Flow Diagram

I have the following question and solution below. What I don't understand is why is the 100,000 seen as savings/revenue when clearly it is coming out of pocket? Additionally, the monthly loan payment ...
2
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0answers
133 views

What does it mean to “pass to the limit” in mathematics?

I've been reading a finance paper and stumbled upon this phrase. What does passing to the limit mean in this context (or overall in mathematics)? Here is an excerpt from the paper: It is ...
2
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0answers
43 views

Reinvesting the interest (generalized version)

If I deposit \$1 at $t=0$ into an account which credits interest at the end of each year at a force of interest $\delta_t$ (assume it's integrable.) Then, if I reinvest the interest at an annual ...
2
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2answers
56 views

quartely payment

A Loan of R65 000 with an interest rate of 16% per annum compounded quartely is to be amortised by equal quartely payments over 3 years Question : how do I calculate the size of the quartely payment? ...
2
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1answer
75 views

first order differential question

Mr. John want to buy a house and he must borrow $150,000 from the bank. He wants a 30-year mortgage and he has 2 choice. Choice #1, he can borrow money at 7% per year with no point ( each point is ...
2
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0answers
37 views

Stochastic control, numerical, need expectations given coupled SDEs

I'm looking at a trio of processes which arises in a stochastic control situation. I have a process $(V_t)$ which I may control, and $(V_t)$ influences a diffusive stock price process $(S_t)$. The ...
2
votes
1answer
52 views

Financial Bonds 500 $1,000 bonds with stated rate of 5% issued at par. 10 year term and pay interest semi-annually.

Every time I try and calculate this problem something comes up wrong. Either from working it out by hand or using my BA II plus, I cannot get the answer shown below. Am I wrong or is this book answer ...
2
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0answers
82 views

Doob Decomposition of American Option

I am trying to figure out the Doob decomposition of an American put option in a discrete time binomial model. I know how to price the American put, but I'm having trouble expressing it as the sum of ...
2
votes
0answers
28 views

Standard practice for identifying outlying spend amounts

Hope this is mathematical enough to qualify as a question - I'm no mathematician! I have a set of individuals travel & entertainment credit card spend, and I'd like to highlight any outliers that ...
1
vote
4answers
1k views

Second Price Auction (Generalized Second Price)

I am trying to find out why we pay second price, but can not understand it. All that I found it is an explanation that it is a real market price, but why it is ? May be some example helps me. For ...
1
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3answers
118 views

Paying Debt Off in a year

I want to know how to calculate minimum fixed monthly payment needed in order to pay off a credit card balance within 12 months. I just want to understand the concept, and how to work around this ...
1
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2answers
85 views

Why can moving averages of the prices indicate the trend of a stock?

In technical analysis of stock trading, we can use the moving averages of the historical prices of a stock to indicate whether it is currently in the uptrend or downtrend. Let me exemplify the idea ...
1
vote
1answer
442 views

today's price of a European put option with payoff $(K-S_1)^+$

I'm trying to calculate the today's price of a European put option, which strikes at price $K$, so that the payoff is $(K-S_1)^+$, in an arbitrage-free, one-period market. As of now, I can only think ...
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2answers
1k views

Calculating interest rate of car financing

I want a new car which costs $\$26.000$. But there's an offer to finance the car: Immediate prepayment: $25\%$ of the original price The amount left is financed with a loan: Duration: $5$ years, ...
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2answers
171 views

how seconds per year does the average worker work?

Approximately how many seconds per year does the average 18 – 21 year women factory worker work? Choices are... A] 2,526 B] 80208 C] 5700 D] 3,443 E] 3958 assuming Accident per person per year is ...
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2answers
44 views

What is a discount?

I am learning some financial terms and am having trouble understanding what a discount $d$ is. Numerically, I understand that it is defined as $\frac{i}{1+i}$ but I do not intuitively understand what ...
1
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2answers
149 views

Solving i for annuities equation without financial calculator

I would like to know if there was a way to approximate i here without a financial calculator, in the following equation: $\displaystyle -50000 + \frac{12992}{1+i} + \frac{12992}{(1+i)^2} + ⋯ + ...
1
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4answers
5k views

No-Arbitrage Principle

I hope you do not mind me asking a financial question in this section. I am having trouble understanding the concept of the no-arbitrage principle for a particular example in my notes: Suppose a ...
1
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1answer
192 views

Interest of interest calculations without logarithm

I have some problems understanding a question in a math class test for 10 year olds. The question is: Someone pays in 200€ to a bank. The interest rate is 3.75%. Some time later, he looks at the ...
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2answers
45 views

Amortize the debt problem

Monthly payments are made on 130000 dollars at 5% for 25 days. Determine the payment needed to amortize the debt.
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2answers
141 views

Find prize per unit that will maximize profit at a given $x$-value

Struggling while reviewing my old math books. The problem has a prize-function and wants to know how the prize-per-unit should be chosen to maximize the profit at $\mathbf{x=160}$. First I look ...
1
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1answer
48 views

How do i solve this to find PMT?

I know this may seem like a stupid question but i've been up late working on this math assignment and this question just isn't working when i transpose it. So this is the formula to find Present ...
1
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1answer
14 views

Finding the compounding period

The future value of a 200 deposit in an account that earns 6.25% annual interest is $272.71 after 5 years. Determine the compounding period for this investment. This is what I have done: $272.71= ...
1
vote
1answer
908 views

Black-Scholes PDE to heat equation, nonconstant coefficients

Can someone provide me with details or a reference on how to transform the Black-Scholes PDE with nonconstant coefficients (i.e. $r=r\left(S,t\right)$, $\sigma=\sigma\left(S,t\right)$) to the heat ...
1
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3answers
99 views

If you invest $\$1500$ at $7\%$ compounded annually, how many years would it take for your investment to grow

If you invest $\$1500$ at $7\%$ compounded annually, how many years would it take for your investment to grow to $3750$? Is this right? $$\text{term } = \frac{\log( \text{overall gain factor})}{ ...
1
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3answers
10k views

Most efficient method for converting flat rate interest to APR.

A while ago, a rather sneaky car salesman tried to sell me a car financing deal, advertising an 'incredibly low' annual interest rate of 1.5%. What he later revealed that this was the 'flat rate' ...
1
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2answers
210 views

at a nominal rate of interest of 8% converted semiannually…Find the initial amount of the loan.

A loan is to be repaid with level instalments payable at the end of each half-year for $3$ and $\frac{1}{2}$ years, at a nominal rate of interest of 8% converted semiannually. After the $4^{\rm th}$ ...
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2answers
278 views

Profit and Loss calculation: Fake currency

A store buys an item for $\$50$. They price it then, at $\$80$ ($\$30$ profit margin). A customer buys the item from them with a fake $\$100$ note. The store returns $\$20$ to the customer. My ...
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2answers
113 views

How to solve for $i$ and $n$ in compound interest formula?

Given that $$F = A{ (1+i)^n - 1 \over i}$$ How can you solve for $i$ or $n$?
1
vote
1answer
182 views

How to compute ideal investment leverage ratio based upon volatility? [closed]

I want to compute the ideal investment leverage ratio based upon an investment's volatility. For example, if I had an investment that with 50% likelihood quadruples your investment on a given day ...
1
vote
1answer
7k views

How do you calculate “excess returns”?

(Although this is perhaps a very simple question, math-wise, it still has me puzzled so it's okay to ask for help here I guess. I really need to understand this, so any help is appreciated) First, ...
1
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2answers
23k views

Calculate gross salary when knowing the net salary and tax brackets

Assume the annually gross salary is $100,000. Tax brackets: 0 - 50K - 10% = 5K in taxes 50K - 70K - 20% = 4K in taxes 70K - $90K - 30% = 6K in taxes 90K and up - 40% = 4K in taxes The income tax ...
1
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2answers
102 views

Calculate breakeven when fixed revenue being added per month v/s cost

I am writing up a cost sheet for a product and I basically suck at math. Didn't know who else to turn to, so trying out Math exchange. So, I am planning to spend ...
1
vote
1answer
212 views

Binomial model of stock price

I've got a homework question which I think I have solved but am not certain if the answers are correct. The question goes like this: Consider a stock which has a 50% chance of increasing by 80% by the ...
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2answers
187 views

Stochastic/finance monte carlo question

When pricing a european option by monte carlo over 30 days for instance, what's the difference between one big 30 day jump vs 30 one day steps?
1
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1answer
33 views

Why would an investor want the minimum yield?

I am puzzled by a problem related to bonds. When a bond is callable, the purchase price (present value of the bond) can fluctuate and I also understand the difference when the bond is purchased at a ...
1
vote
2answers
20 views

Help for calculating the correct marked price?

A) For this equation I need help calculating the marked price. A retailer wants to make a 22% profit on the sale of a television set. The television set cost the retailer $560. What should the ...
1
vote
1answer
26 views

Time required to make money 6 times of itself

A sum doubles itself in one year at a certain rate of interest, compounded annually. In how many years will a sum become six times itself under the same investment scheme? I got confused in this ...
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1answer
29 views

Calculating the yearly payment in a loan. Amortization with unequal payments.

The following is the problem that I am working on. A 30-yr loan of $1,000$ is repaid with payments at the end of each year. Each of the first ten payments equals the amount of interest due. Each ...
1
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1answer
68 views

books on the application of linear algebra on statistics/finance/machine learning

I am reading "linear algebra done right" by Axler and like it a lot. One thing though, in the end I would like to put these theory to use and as a math textbook it doesn't cover much application. ...
1
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1answer
21 views

The meaning of “average annual compound rate”

I am currently working on this problem and I am having a hard time finding the right number. A mutual fund advertises that average annual compound rate of returns for various periods ending Dec 31 ...
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1answer
37 views

Effective interest rate given two loan payment options…

Here's the full problem: You have two options to repay a loan. You can repay $\mathbb{$}6000$ now and $\mathbb{$}5940$ in one year, or you can repay $\mathbb{$}12000$ in $6$ months. Find the ...
1
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2answers
35 views

Bactracking to find compound interest

I'm trying to find what percentage 5000 dollars compounding monthly over 120 months will be if the final sum will be 7000 dollars. So: 7000=5000(1+r/12)^120 When working backwards to find r I ...
1
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2answers
66 views

How much more than will you pay on a 30 year mortgage than if you paid it all up front?

There are hundreds of loan calculators online but none of them tell me this, Say I take out a 30 year mortgage on a 80,000 dollar house for 4% interest. How much more than $80k will I spend at the ...
1
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2answers
46 views

Basic question mathematical finance, law of one price in single period markets.

I am reading Pliskas Introduction to mathematical finance. And I am at single period models. It is the law of one price I am having a hard time of understanding. I have some questions about this: ...