Question

If I flip four coins what is the probability that at least two of the coins are heads?

Answer 1

Please help

Answer 2

its the opposite of P(at most 1 is heads)

Answer 3

1 - P(0) - P(1)

Answer 4

do you have choices

Answer 5

there are 16 outcomes

tttt

ttth
ttht
thtt
httt

...
1 4 6 4 1 = 16

0 heads is 1 out of 16
1 head is 4 out of 16

Answer 6

What about at least 2 heads

Answer 7

at least 2 heads means that you have 2, 3, or 4 heads

P(0) + P(1) + P(2) + P(3) + P(4) = 1

P(2) + P(3) + P(4) = 1 - P(0) - P(1)

Answer 8

since P(0) = 1/16
and P(1) = 4/16

the solution is determined

Answer 9

So what would the answer be written as?

Answer 10

im not going to do the subtraction for you ....

Answer 11

you can tell me what you get ... and i can verify if you did it correctly

Answer 12

bro your even confusing me.... amistre64

Answer 13

im not a mind reader, so youll have to be more detailed in what is confusing :)

Answer 14

nevermind .. the probability would be 50% John

Answer 15

the probability is not 50%; for starters, a probability is a number between 0 and 1 ... not a percentage.

Answer 16

and for another, 1 - P(0) - P(1) does not equal .5000 or 1/2

Answer 17

he asked for a probability. if you flip 4 coins and the odds of 2 of the comming out heads is 2/4 and tht equals 50%
and wtf is p

Answer 18

its not rocket science he just wants a simple answer.. idk whats wrong with tht

Answer 19

\[\binom{4}{0}.5^0.5^4+\binom{4}{1}.5^1.5^3+\binom{4}{2}.5^2.5^2+\binom{4}{3}.5^3.5^1+\binom{4}{4}.5^n.4^0=1\]
\[(1).5^0.5^4+(4).5^1.5^3+(6).5^2.5^2+(4).5^3.5^1+(1).5^4.5^0=1\]

Answer 20

P(E) is notation for "probability of an event"

Answer 21

the last 3 terms are 4 choose 2, 4 choose 3, and 4 choose 4 which is what we want if we are to determine "at least 2" out of 4

Answer 22

subtracting the first 2 terms from each side gives us the solution

Answer 23

your making this way more complex than it already isnt lol if you know the damn answer then tell him and quit arguing with a degenerate!

Answer 24

i suggest you tone down your language. and, we are not providing a free answering service, we are offering a way to learn the material.

Answer 25

my first attempt was to simplify it .... since that did not work i resorted to the longer, more detailed version of it all.

Answer 26

So the answer is .6875?

Answer 27

Or 11/16

Answer 28

11/16 is correct either way is fine, but the format is up to whoever is doing the grading.

Answer 29

Thanks I just forgot how to do this from the beginning of the year

Answer 30

you did fine :) good luck