Mathematical Modeling in Finance with Stochastic Processes

(Ben Green) #1

4.4 The Absolute Excess of Heads over Tails


distributionXwith a parameter 1/100 which implies thatE[X] = 100
and Var [X] = 100^2. The company can afford some overstatements sim-
ply because it is cheaper to pay than it is to investigate and counter-
claim to recover the overstatement. Given 100 claims in a month, the
company wants to know what amount of reserve will give 95% cer-
tainty that the overstatements do not exceed the reserve. (All units
are in dollars.) What assumptions are you using?

Outside Readings and Links:



  1. Virtual Laboratories in Probability and Statistics. Search the page for
    Binomial approximation and then run the Binomial Timeline Experi-
    ment.

  2. Central Limit Theorem explanation Pretty good visual explanation of
    the application of the Central Limit Theorem to sampling means.

  3. Central Limit Theorem explanation Another lecture demonstration of
    the application of the Central Limit Theorem to sampling means.


4.4 The Absolute Excess of Heads over Tails


Rating


Mathematically Mature: may contain mathematics beyond calculus with
proofs.


Section Starter Question


What does the law of averages have to say about the probability of having a
fixed lead of say 20 Heads or more over Tails or 20 Tails or more over Heads
at the end of a coin flipping game of some fixed duration? What does the
Weak Law of Large Numbers have to say about having a fixed lead? What
does the Weak Law have to say about having a proportional lead, say 1%?
What does the Central Limit Theorem have to say about the lead?

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