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#### Probability Density Function

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Published: 05 December 2019
Fig. 5 Probability density function of birth weight before and after the water switch More
Journal Article
Demography (1977) 14 (1): 103–104.
Published: 01 February 1977
...K. B. Pathak; C. V. S. Prasad Abstract A model to estimate adolescent sterility among married women is presented using the principle of convex combination of two or more probability density functions. 12 1 2011 © Population Association of America 1977 1977 Density Function...
Journal Article
Demography (1989) 26 (3): 451–465.
Published: 01 August 1989
... childbearing with M boys, then the variable X has a negative binomial distribution (which becomes a geometric distribution when M = 1) with the probability density function that is given in formula (2). Since each family has the same number of M boys under this stopping rule, the distribution of boys becomes...
Journal Article
Demography (1972) 9 (1): 1–11.
Published: 01 February 1972
... function (p.d.f.) is there- fore .. f(x) = 1: p,f,(x), i-I with the probability density function of the i-th sub-population being f ( ) x = T,e . We assume that the IUD retention rate is a complement of the cumulative density function form of a two-fold mixed exponential function. Figures 1 and 2 show...
Journal Article
Demography (1992) 29 (2): 227–245.
Published: 01 May 1992
... the probability of the ith birth in the age interval (x,x + dx) and the probability of no birth in the age interval (y,x). The unconditional density function of age at birth order i is obtained as xJg,{xly)g;_iy)dy. a (8) Age at Last Birth and Its Components The probability of ever having an ith birth, Fi...
Journal Article
Demography (2003) 40 (2): 201–216.
Published: 01 May 2003
... da w a t da ( ) ( , ) ( , ) ( , ) ,= 0 0 (5) where w(a,t) is some weighting function. We define the average improvement in mortality as ( ) ( , ) ( , ) ,t a t f a t da= 0 (6) where f(a,t) is the probability density function describing the distribution of deaths (i.e., life spans) in the life...
Journal Article
Demography (1988) 25 (2): 249–263.
Published: 01 May 1988
... that in an ideal environment, age at death is simply S7. Letting r~i = Xi - gO(Ki) and denoting the probability density function of u7by h(uf), then the probability (xqOi) that i will be dead by age X can be written AOi = J~~ h(un duj , and the probability (lxi) that i will survive from birth to age X is (6) (7...
Journal Article
Demography (1990) 27 (1): 149–163.
Published: 01 February 1990
... is the dilference between the midpoints of the two age intervals, then the probability density function of x can be used to derive the preliminary estimates of the transition probabilities. A probability density function that incorporates the gravity principle and is continuous at x = 0, can be written as' -0 x 0...
Journal Article
Demography (1979) 16 (2): 329–338.
Published: 01 May 1979
...). (11) This probability density function is the continuous analogue of equation (7). The continuous analogues of (8) and (10) are H 2 = - {'p(x)lnp(x)dx (12) o and e, = - f"'p(x) Inx)m(x)] dx. (13) o The generation time or the mean age of women giving birth is given by T2 = {"x p(x) dx, o In this case...
Journal Article
Demography (2001) 38 (1): 79–95.
Published: 01 February 2001
... density function (pdf) for ages at death will sta- bilize at some distribution. A life span limit is not a neces- sary precursor to this hypothesis (see Wilmoth 1997; Wilmoth and Horiuchi 1999), nor does it imply a reduction in variance for the pdf for ages at death over time, as implied...
Journal Article
Demography (1986) 23 (2): 275–282.
Published: 01 May 1986
...) and from that applied to general probability density functions (see, for example, Theil 1972). Equation (7) tells us that for a small proportional reduction 8 in the death rate at all ages, the proportional increase in life expectancy can be simply approximated as H times 8. The value of H depends directly...
Journal Article
Demography (1972) 9 (2): 309–320.
Published: 01 May 1972
...). The impulse re- sponse hi (t) can be interpreted as the weighted probability density function of spacing time between Oth and 1st parity with 1o h1(t) dt = K 1. The density function interpretation of hi (t) indicates that a 1st order system 313 will suffice for parities greater than 0 since...
Journal Article
Demography (1983) 20 (2): 177–195.
Published: 01 May 1983
... become widows, for those who eventually do so, requires normalization of the function f(x, k, t), in order to obtain a probability density function: Sex Differences in Life Cycle Measures of Widowhood Table 3.-Median Ages of Brides and Grooms, 1940-1979 181 Difference Year Bride Groom (Years) 1940 23.2...
Journal Article
Demography (1978) 15 (4): 499–507.
Published: 01 November 1978
... of (16): Simple algebra reveals that the above ratio equals twice the variance of m(x), 2uz However, since ~E[f(x)] f:. E[H(x)] for general probability density functions f(x), K cannot be expressed as a constant multiple of (J. Nevertheless, nu- merical calculations of K and a for 49 schedules...
Journal Article
Demography (1976) 13 (2): 225–233.
Published: 01 May 1976
... and the unmarried, then it is well known that the proportion ever married G(a) is equal to the integral of g(x) up to a: G(a) = f g(x) dx . (5) If g(a) is normalized by dividing through by the proportion who ever marry E = G(w), then g*(a) = g(a)/E is a proper probability density function. This proba- (7b) 228...
Journal Article
Demography (2022) 59 (1): 207–220.
Published: 01 February 2022
..., for example—with probability density function f ( y ) and a mean of E [ Y ] &gt; 0 . The length-biased distribution arising from f ( y ) has the following density: f l b ( y ) = y f ( y ) E [ Y ] . (1) The mean of this length-biased...
FIGURES
Includes: Supplementary data
Journal Article
Demography (1990) 27 (1): 97–109.
Published: 01 February 1990
.... The hazard function that we use results from a mixture of two densities from the gamma family of probability density functions. Let a and b be the parameters of the two component densities and <51 and <52 be the mixing coefficients such that <51 + <52 = 1. The hazard function can be written as follows: o(t...
Journal Article
Demography (1989) 26 (2): 287–299.
Published: 01 May 1989
... a birth while in a given state. We define hij(t) as the hazard rate of moving from state i to state i, where t is duration, i is either employment or nonemployment, and i is either employment, nonemployment, or a birth. The conditional probability density function can then be written as hjj(t) = gi;(t)/Sj...
Journal Article
Demography (1981) 18 (2): 231–244.
Published: 01 May 1981
.... Hoem, Britta and Carsten Torpe. 1977. Regionale fertilitetsforskelle 1971-1976. Danmarks Statistik, Statistiske Undersøgelser #35. Hoem Jan M. ( 1971 ). On the Interpretation of the Maternity Function as a Probability Density . Theoretical Population Biology , 2 , 319 – 327 . 10.1016...
Journal Article
Demography (2013) 50 (5): 1615–1640.
Published: 17 September 2013
... ), is (56) The interquartile range is defined implicitly in terms of the distribution of ages at death. Let be a probability density function and be the cumulative distribution. The q th quantile is the value satisfying (57) Let and , assuming that q 2 &gt; q 1...
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Includes: Supplementary data