SOLUTION: A random research committee of size 5 is selected from 7 lecturers and 4 tutors. Write a formula for the probability distribution of the random of the ran

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Question 1032547: A random research committee of size 5 is selected from 7 lecturers and 4 tutors. Write a formula for the probability distribution of the random of the random variable Y representing the number of tutors on the committee. Find: a. P(1 ≤ Y ≤ 3) b. P(Y ≤ 1) c. E(Y ) and V (Y )
Answer by robertb(5830) About Me  (Show Source):
You can put this solution on YOUR website!
P%28Y+=+0%29+=++%28%287C5%29%284C0%29%29%2F%2811C5%29+=+1%2F22,
P%28Y+=+1%29+=++%28%287C4%29%284C1%29%29%2F%2811C5%29+=+10%2F33,
P%28Y+=+2%29+=++%28%287C3%29%284C2%29%29%2F%2811C5%29+=+5%2F11,
P%28Y+=+3%29+=++%28%287C2%29%284C3%29%29%2F%2811C5%29+=+2%2F11,
P%28Y+=+4%29+=++%28%287C1%29%284C4%29%29%2F%2811C5%29+=+1%2F66.
The formula is , for y = 0, 1, 2, 3, 4.
Note that the sum of the probabilities is 1.
a. P(1 ≤ Y ≤ 3) = 10%2F33%2B5%2F11%2B2%2F11+=+31%2F33
b. P(Y ≤ 1) = 1%2F22+%2B+10%2F33+=+23%2F66
c.
d.
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