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Karten 20
Sprache Deutsch
Kategorie Mathematik
Stufe Universität
Erstellt / Aktualisiert 14.10.2024 / 15.10.2024
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\(S_0(t) = \)

\(S_0(t) = Pr(T_0 > t) = {}_tp_0\)

Probability that (0) dies after t periods (years) => survival function of \(T_0\)

where: 

\({}_tp_0\)represents the probability that a person aged x survives for at least t years (the t-year survival probability).

\(T_0\)

Time-until-death of a new-born baby

 

\(F_0(t) = \)

\(F_0(t) = Pr(T_0 ≤ t) = 1- S_0(t) = ...?\)

cummulative distribution function

p.d.f.

Probability Density Function: describes the likelihood of a continuous random variable taking on a particular value, it is used to determine the probability that the variable falls within an interval by integrating the p.d.f. over that interval.

 

Properties of a p.d.f.

- always non-negative

- The total area under the p.d.f. curve equals 1, ensuring that the total probability over all possible values of the random variable sums to 1.

Example of p.d.f.

If \(f_0(t)\) is the p.d.f. of a random variable X, the probability that X falls between two values a and b is given by:

\(P(a≤X≤b)= ∫_{a}^{b} f_x(x)dx\)

 

For a continuous random variable \(T_0\) with a p.d.f. \(f_{T_0}(t)\), the expected value of \(T_0\) is given by:

.

This formula is equal to ? ITO survival function and curtate life expectancy

.

What means \(µ_t\)?

the force of mortality: measures the instantaneous rate of mortality at a specific age x.

Formula, where:

\(f(x)\) is the p.d.f. of the age-at-death r.v. X. X. It describes the likelihood of death at a specific age x.

- S(x) is the survival function, which gives the probability that an individual aged x survives beyond age x.

- also: the force of mortality is the negative derivative of the natural logarithm of the survivor function.

 

Cumulative distribution function (CDF) 

\(F_0(t) = Pr(T_0 ≤ T) = 1 - S_0(t) = tq_0 \)

CDF of the age-at-death random variable, representing the probability of dying at age xxx or earlier.

where:

\(tq_0 \)is the probability that a person aged x will die within the next t years.

 

\({}_tp_x + tq_x = 1\)

\({}_tp_x \) represents the probability that a person aged x survives for at least t years (the t-year survival probability).

\(tq_x \) The probability that a person aged x will die within the next t years.

--> they are complementary probabilities

relation b/w survival function, CDF, P and q

.

Formula? given a specific survival function.

p.d.f. of \(T_0\)

\(µ_t\) formula

relation b/w \(µ_x\) and \({}_xp_0\)

\({}_xp_0\) is the probability that (0) (a person of age 0) dies after x periods (years) and is therefore the same as the survival function \(S_0(t) = Pr(T_0 > t)\)

 

Beta distribution

The random variable X is called a beta random variable if its p.d.f is given by

ITO E[X]

Erwartungswert und Varianz - Regeln

Erwartungswert und Varianz von Summen