If 5 students are chosen at random what is the probablity of selecting 5 students with type "O" blood?
2007-01-07 12:22:11 · 7 answers · asked by Samantha F 1 in Science & Mathematics ➔ Mathematics
P(All 5 have O blood)
= P(1st is O and 2nd is O and ... and 5th is O)
You will see ands here, which means you should use a multplication rule. Now these events are not independent, since these students are selected without replacement (otherwise you chance picking the same student more than once). You can still multiply, but you need to be more careful.
(80/200)(79/199)(78/198)x
(77/197)(76/196)
= 0.00948
2007-01-07 12:25:48 · answer #1 · answered by blahb31 6 · 3⤊ 0⤋
5/200 * 0â4 = 2/200 = 1/100 = 1%
2007-01-07 20:30:10 · answer #2 · answered by Brenmore 5 · 0⤊ 1⤋
This is sampling without replacement.
p(5O | 5) = (80*79*78*77*76)/(200*199*198*197*196)
= .00948081
2007-01-07 20:28:30 · answer #3 · answered by Northstar 7 · 1⤊ 0⤋
If all five have to have type O blood:
(80/200)^5
If want at least one to have type O but they don't all have to have it:
(80/200)*5
2007-01-07 20:27:36 · answer #4 · answered by zandyandi 4 · 0⤊ 2⤋
0dds are 2/5 that one has type O so you take 2/5x2/5x2/5x2/5x2/5 which equals 32/3125 or just over 1% chance.
2007-01-07 20:27:46 · answer #5 · answered by John G 4 · 0⤊ 2⤋
(80/200)^5
0.0063582343481257489863459401059292
~0.636%
...i think
2007-01-07 20:25:27 · answer #6 · answered by Dashes 6 · 0⤊ 1⤋
0.94% is this your homework?
2007-01-07 20:32:25 · answer #7 · answered by sushimaven 4 · 0⤊ 1⤋