Question

1. An urn contains ten marbles of which five are green, two are blue, and three are red. Three marbles are to be drawn from the urn, one at a time without replacement. What is the probability that all three marbles drawn will be green? 2. In Southern California, a growing number of individuals pursuing teaching- credentials are choosing paid internships over traditional student teaching programs. A group of eight candidates for three local teaching positions con- sisted of five who had enrolled in paid internships and three who enrolled in traditional student teaching programs. All eight candidates appear to be equally qualified, so three are randomly selected to fill the open positions. Let Y be the number of internship trained candidates who are hired. Does Y have a binomial or hypergeometric distribution? Why? Find the probability that two or more internship trained candidates are hired What are the mean and standard deviation of Y?

Answer 1

An uen contains l_maebles: These are 5 gelen 2 blue and _3_sed maebles. Theee_maebles are deawn without Eeplacement. Fiest maeble to draw has 10 choices. second maeble has g choices. Because ist marble is already deawn and we have given that marbles are deawn without Eeplacement. llow two maεbles are drawn. We have 8 maεbles. -Thied marble has & choices. .. Total numbeɛ of ways to draw _3_marbles__ = 10x9x8 =920 Now, condition is that all three _marbles deawo will be geeen. We have 5 geeen marbles. Fest maeble has 5 choices. Second has 4 choices: (2 without Eeplacement)| Thiedma eble has 3 choices. ... Total numbee at ways to draw 3 - geeenmaebles = 5x4x3 = 60

sor Requized peobability L = 60 720 _ 72 = 0.0833333333
answer of 1.