The average number of children a Japanese woman has in her lifetime is 1.37. Suppose that one Japanese woman is randomly chosen. a. In words, define the random variable X. b. List the values that X may take on. c. Give the distribution of X.X~ _____(_____,_____) d. Find the probability that she has no children. e. Find the probability that she has fewer children than the Japanese average.

Respuesta :

Answer:

a. X: amount of children that a Japanese woman has in her lifetime.

b. X can take natural numbers (all positive integers) as values.

c. X~Poi(1.37).

d. P(X=0)=0.2541

e. P(X<1.37)=0.6022

Step-by-step explanation:

a) This can be modeled with a Poisson distribution.

We let the variable X be the amount of children that a Japanese woman has in her lifetime.

The parameter of the Poisson distribution is λ=1.37.

This is also the value of the mean and the standard deviation.

b) X can take all positive integer values.

c) X is modeled as a Poisson variable with λ=1.37.

d) This can be calculated as:

[tex]P(0)=\lambda^ke^{-\lambda}/k!=1.37^{0} \cdot e^{-1.37}/0!=1*0.2541/1=0.2541\\\\[/tex]

e) Having fewer children than the average means that she has one or none children.

This can be calculated as:

[tex]P(X<1.37)=P(0)+P(1)\\\\\\P(0)=1.37^{0} \cdot e^{-1.37}/0!=1*0.2541/1=0.2541\\\\P(1)=1.37^{1} \cdot e^{-1.37}/1!=1.37*0.2541/1=0.3481\\\\\\P(X<1.37)=0.2541+0.3481=0.6022[/tex]