Consider a binomial experiment with n=20 and p=0.70 a) Compute f(12) b)

kloseyq

kloseyq

Answered question

2021-12-21

Binomial experiment with n=20 and p=0.70 
a) Compute f(12) 
b) Compute f(16) 
c) Compute P(x16) 
d) Compute P(x15) 
e) Compute E(x) 
f) Compute var(x) and σ

Answer & Explanation

David Clayton

David Clayton

Beginner2021-12-22Added 36 answers

Step 1 
Given: 
p=0.70 
n=20 
Binomial probability formula:
f(k)=(nk)×pk×(1p)nk 
a) f(12)=(2012)×0.7012×(10.70)2012=0.114397 
f(16)=(2016)×0.7016×(10.70)2016=0.130421 
c) Add the associated probabilities:
P(X16)=f(16)+f(17)+f(18)+f(19)+f(20)=0.2375 
d) For probabilities, apply the complement rule:
P(X15)=1P(X16)=10.2375=0.7625 
Step 2 
e) The mean of binomial distribution is the product of the sample size n and the probability p: 
μ=np=20×0.20=14 
f) The standard deviation of a binomial distribution is the square root of the product of the sample size n and the probabilities p and q. The variance is the square of the standard deviation. 
σ2=npq=np(1p)=20(0.70)(10.70)=4.2 
σ=npq=np(1p)=20(0.70)(10.70)2.0494

levurdondishav4

levurdondishav4

Beginner2021-12-23Added 38 answers

Step 1 
Wherever a random variable X can be modeled as a binomial random variable we write : 
XBi(n, p) 
Where n is the number of Bernoulli experiments taking place (whose variable is called binomial random variable). 
And where p is the success probability. 
In a Bernoulli experiment we define which event will be a success 
In order to calculate the probabilities for the variable X we can use the following equation : 
P(X=x)=f(x)=(nCx)×(px)×(1p)nx 
Where P(X=x) is the probability of the variable X to assume the value x. 
Where nCx is the combinatorial number define as : 
nCx=n!x!(nx)! 
In our question 
XBi(20, 0.70) 
Now lets

nick1337

nick1337

Expert2021-12-27Added 777 answers

Step 1
NSK
Given that X is binomial n=20; p=0.70
a) Compute f(12) (to 4 decimals).
=0.1144
b) Compute f(16) (to 4 decimals).
=0.1304
c) Compute P(x16) (to 4 decimals)
=0.7624
d) Compute P(x15) (to 4 decimals).
=0.5836
e) Compute E(x)=np=14
NSK
f) Compute Var(x) (to 1 decimal) and (to 2 decimals).
Var(x)=npq=4.2

star233

star233

Skilled2023-05-10Added 403 answers

Answer:
a) f(12)=20!12!·8!·(0.70)12·(0.30)8
b) f(16)=20!16!·4!·(0.70)16·(0.30)4
c) P(X16)=x=1620(20x)(0.70)x(10.70)20x
d) P(X15)=x=015(20x)(0.70)x(10.70)20x
e) E(X)=20·0.70
f) Var(X)=20·0.70·(10.70)
σ=20·0.70·0.30
Explanation:
a) To compute the probability mass function (PMF) for a binomial experiment with n=20 and p=0.70, we can use the formula:
f(x)=(nx)px(1p)nx
where (nx) represents the binomial coefficient. Now let's calculate f(12).
f(12)=(2012)(0.70)12(10.70)2012
Calculating the binomial coefficient:
(2012)=20!12!(2012)!
Simplifying:
(2012)=20!12!·8!
Substituting the values back into the formula:
f(12)=20!12!·8!·(0.70)12·(10.70)2012
Calculating the value:
f(12)=20!12!·8!·(0.70)12·(0.30)8
b) Now, let's compute f(16) using the same formula:
f(16)=(2016)(0.70)16(10.70)2016
Using the binomial coefficient:
(2016)=20!16!(2016)!
Simplifying:
(2016)=20!16!·4!
Substituting the values back into the formula:
f(16)=20!16!·4!·(0.70)16·(10.70)2016
Calculating the value:
f(16)=20!16!·4!·(0.70)16·(0.30)4
c) To compute P(X16), we need to sum up the probabilities of all values greater than or equal to 16. It can be calculated as:
P(X16)=x=1620(20x)(0.70)x(10.70)20x
d) Similarly, to compute P(X15), we sum up the probabilities of all values less than or equal to 15:
P(X15)=x=015(20x)(0.70)x(10.70)20x
e) To compute the expected value (mean) of the binomial distribution, we can use the formula:
E(X)=np
where n is the number of trials and p is the probability of success.
Substituting the values:
E(X)=20·0.70
f) The variance of a binomial distribution can be calculated using the formula:
Var(X)=np(1p)
where n is the number of trials and p is the probability of success.
Substituting the values:
Var(X)=20·0.70·(10.70)
Calculating the variance:
Var(X)=20·0.70·0.30
The standard deviation, denoted as σ, can be obtained by taking the square root of the variance:
σ=Var(X)
Substituting the calculated variance:
σ=20·0.70·0.30
Calculating the standard deviation:
σ=12.6
alenahelenash

alenahelenash

Expert2023-05-10Added 556 answers

a) To compute f(12), the probability mass function of a binomial distribution can be used. The formula for f(x) is:
f(x)=(nx)·px·(1p)nx
where n is the number of trials and p is the probability of success.
In this case, n=20 and p=0.70. Substituting these values into the formula, we have:
f(12)=(2012)·0.7012·(10.70)2012
Calculating this expression will give us the probability of getting exactly 12 successes in 20 trials.
b) Similarly, to compute f(16), we use the same formula:
f(16)=(2016)·0.7016·(10.70)2016
c) To compute P(X16), we sum the probabilities of all outcomes from 16 to 20:
P(X16)=f(16)+f(17)+f(18)+f(19)+f(20)
d) To compute P(X15), we sum the probabilities of all outcomes from 0 to 15:
P(X15)=f(0)+f(1)+f(2)++f(15)
e) The expected value, or the mean, of a binomial distribution can be calculated using the formula:
E(X)=n·p
where n is the number of trials and p is the probability of success. In this case, n=20 and p=0.70.
f) The variance and standard deviation of a binomial distribution can be calculated using the formulas:
Var(X)=n·p·(1p)
σ=Var(X)
where n is the number of trials and p is the probability of success. In this case, n=20 and p=0.70.

Do you have a similar question?

Recalculate according to your conditions!

New Questions in High school probability

Ask your question.
Get an expert answer.

Let our experts help you. Answer in as fast as 15 minutes.

Didn't find what you were looking for?