Question

What is the theoretical probability of landing on heads if you flip a coin 100 times and land on heads 28 times?

Answer 1

Do the same for 31, and 41.

Answer 2

@Mehek14

Answer 3

I'm not that good at probability

Answer 4

Ok but can you try? Nobody has helped me and I've been at this for almost 2 hours :(

Answer 5

@KendrickLamar2014

Answer 6

@iGreen

Answer 7

ok

Answer 8

@~Samson245~

Answer 9

@DarkMoonZ @camerondoherty

Answer 10

@Godlovesme

Answer 11

sowwy i suck at probability :(

Answer 12

Ok :']

Answer 13

@freckles

Answer 14

I read your question a couple of times and I can't make of sense of it.
What is the probability of landing on heads 100 times and landing on heads 28 times?

Answer 15

no, what is the theoretical probability of landing on heads 28 times when you flip a coin 100 times

Answer 16

oh yeah i messed up in d question

Answer 17

PLEASE HELP!!!!!!!!!!!!!!!!! I DONT HAVE TIME AND THIS IS DRIVING ME CRAZY!!!!!!!!!!!!!!!!!!!!!!

Answer 18

@CallMeKiki

Answer 19

Ok that makes a little more sense
say we wanted to know the probability of landing heads 1 times when we flip the coin say 3 times...

Well if we flip the coin 3 times these are the possibilities:
TTT
TTH
THH
THT
HTH
HTT
HHH
HHT

There are 8 possibilitites but only 3 of these have H 1 times.
So the probability of getting 1 heads given 3 tosses would be 3/8
So the probability of getting 2 heads given 3 tosses would be 3/8
So the probability of getting 0 heads given 3 tosses would be 1/8
The probability of getting 3 heads gives 3 tosses would be 1/8

So hmm... how can we get the denominator for your problem...
Well for the example the 8 comes from doing 2^3
The 3 comes from the number of tosses and the 2 comes from the possible head or tails outcome.

So I think you can find your denominator pretty easily now.

As for the numerator...
Well let's think about the previous example
what is 3 choose 1
what is 3 choose 2
what is 3 choose 0
what is 3 choose 3

Answer 20

choose?

Answer 21

\[n \text{ choose k} \text{ is the same as saying } \left(\begin{matrix}n \\ k\end{matrix}\right)\]

Answer 22

So you could develop a formula for this
Suppose 0<k<n
where k and n are integers of course.

The probability of getting k heads given n tosses is:
\[\frac{\left(\begin{matrix}n \\ k\end{matrix}\right)}{2^n}\]

Answer 23

wow

Answer 24

how do u solve?

Answer 25

I gave you formula
try to use it

Answer 26

what is your k and what is your n given

Answer 27

hmm.....

Answer 28

i dont know for real.... im REALLY not good at math :(

Answer 29

"The probability of getting k heads given n tosses is:"
Going back to part of the formula I gave...
So you don't know how to determine what your k and n is from this?
you don't know how many tosses you have
or the number of heads you want?

Answer 30

oh 28/100

Answer 31

no no...
I'm asking what is k and what is n
k i 28 and n is 100
so go back to the rest of the formula I gave and enter those in

Answer 32

yup, n 28 k 100?

Answer 33

The probability of getting k heads given n tosses is:
\[\frac{\left(\begin{matrix}n \\ k\end{matrix}\right)}{2^n} \]
you have:
The probability of getting 28 heads given 100 tosses is
\[\frac{\left(\begin{matrix}100 \\ 28\end{matrix}\right)}{2^{100}} \]

Answer 34

I suggest leaving it just like that because both top and bottom are really huge

Answer 35

haha ok so then can you tell me the final answer?

Answer 36

that is the final answer

Answer 37

ok is it (100/28) / 2 (tiny)100 ?

Answer 38

is that the answer?

Answer 39

no

Answer 40

100 choose 28 is not the same as 100/28

Answer 41

oh

Answer 42

can you also help with these?
http://openstudy.com/users/77777jeannie77777#/updates/54f76bdee4b0c8e441be8634

Answer 43

look at the document

Answer 44

please i need help with #3, #5

Answer 45

you know you are flipping two coins not 1

Answer 46

yeah i said that right?

Answer 47

for this problem we only flipped one coin

Answer 48

AHHH OH NO !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 49

flipped one coin hundred times that is

Answer 50

omg can u pls just tell me the answer

Answer 51

anyways i might help later
i must go

Answer 52

no i already flipped 2

Answer 53

please!!! i barely have time :'(

Answer 54

i just forgot to mention that it was 2

Answer 55

@inowalst

Answer 56

@77777jeannie77777 just so you know the question you asked here on this page is way more advanced than any question given to you on your paper (that is probably why you didn't know what n choose k meant)

I think if you follow what @directrix said you have what you really seek

you asked me what is the Probability of getting 28 heads given 100 tosses...
None of your questions asked that

What is probability of getting two heads given a coin (where you have two coins) toss was already answered actually... Follow what @directrix has given you.