TITLE: Probability calculation of a project group - Stochastics
QUESTION [0 upvotes]: A project group is to be put together. For this purpose, 42 employees are available, of whom 19 have already worked in the field. The rest not. There are 11 employees randomly selected. What is the probability that exactly 4 experienced employees will be assigned to the group? The result should be rounded to 2 digits after the comma!
can anyone help? how to calculate this - my schooltime is long ago.
thx in adv.
Peter

REPLY [0 votes]: You want $4$ experienced employees from $19$, and $7$ employees from the rest $23$, so the probability (assuming each employee is selected equally likely) is $$P = \frac{{19\choose 4}{23\choose 7}}{{42 \choose 11}}$$
To round it up just calculate this fraction.
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