# Need help in Mean, Probability & SD

1. Apr 19, 2007

### sumans

The placement data of a business school suggest that the percentage of students securing a job with a multinational during the years 1996, 1997 and 1998 are 20%, 30% and 40% respectively. One student is chosen at random from the graduating batch of each year. Let X be the number of students, out of the three so selected who had secured a job with a multinational. Calculate the following:

a) The probability distribution of X
b) The Mean of X
c) The Standard Deviation of X

2. Dec 16, 2011

### panky05

Can anyone post answer of this?

3. Dec 17, 2011

### SW VandeCarr

Are you asking for sumans? Can't sumans speak for him/herself? In any case, his/her question is over 4 years old and if this was a homework question, it should have been posted in that forum. When posting questions, the poster should show an attempt at a solution.

Last edited: Dec 17, 2011
4. Dec 17, 2011

### micromass

Staff Emeritus
This thread is 4 years old.