Probability: foreign versus domestics birth in California

[flakine]

The Census Bureau reports that 27% of California residents are foreign-born. Suppose that you choose three Californians at random, so that each has probablity .27 of being foreign-born and the three choices are independant of each other. Let the random variable X be the number of foreign-born people you chose.

a) What are the possible values of X?

b) Look at your three people in order. There are eight possible arrangements of foreign (F) and domestic (D) birth. For example, FFD means the first two are foreign-born and the third is not. Write down all eight arrangements and find the probability of each arrangement.

c) What is the value of X for each arrangement in b)? What is the probability of each possible value X?

Any help please!

 

[stapel]

a) If X stands for the number of foreign-born people you chose, and you've picked three people, what are the possible values of X?

b) This is just a matter of listing out the eight permutations.

c) Since the choices of persons were independent of one another, the probabilities of the various arrangements may be handled in the same manner as you would handle the probability of, say, getting three "heads" out of four coin-tosses.

If you get stuck, please reply showing all of your work and reasoning. Thank you!

Eliz.