The probability that a patient recovers from a stomach disease is 0.8. Suppose 20 people are known to have contracted this disease. What is the probability that exactly 14 recover?

CMIIh

CMIIh

Answered question

2021-02-19

The probability that a patient recovers from a stomach disease is 0.8. Suppose 20 people are known to have contracted this disease. How likely is it that exactly 14 will recover?

Answer & Explanation

Latisha Oneil

Latisha Oneil

Skilled2021-02-20Added 100 answers

Let Y be the random variable denoting the number of patients that recover from the stomach disease. Due to the fact that each patient will either recover or not, Y is obviously a binomial random variable. (i.e. has only 2 values).
Here, n=20 and p=0.8
We need to find P(Y=14). This can be found by using Table I in Appendix 3 with n=20 and p=0.8
P(Y=14)=P(Y14)P(Y13)
=0.1960.087
=0.109
Result: P(Y=14)=0.109

Nick Camelot

Nick Camelot

Skilled2023-05-25Added 164 answers

Answer:
0.109
Explanation:
P(X=k)=(nk)·pk·(1p)nk,
where (nk) represents the number of ways to choose k successes from n trials, p is the probability of success, and (1p) is the probability of failure.
In this case, we want to find the probability of exactly 14 out of 20 people recovering from the stomach disease. The probability of an individual recovering is p=0.8, and the number of trials is n=20.
Substituting these values into the binomial probability formula, we have:
P(X=14)=(2014)·0.814·(10.8)2014.
To calculate the binomial coefficient (2014), we can use the formula:
(nk)=n!k!(nk)!.
Plugging in the values, we get:
(2014)=20!14!(2014)!.
Now we can calculate the probability:
P(X=14)=20!14!(2014)!·0.814·(10.8)2014.
Simplifying further:
P(X=14)=20!14!6!·0.814·0.26.
Calculating the factorials:
P(X=14)=20·19·18·17·16·156·5·4·3·2·1·0.814·0.26.
Now we can evaluate the expression:
P(X=14)=38760720·0.814·0.26.
Simplifying the fraction:
P(X=14)=54·0.814·0.26.
Evaluating the exponents:
P(X=14)=54·(0.82)7·0.26.
Simplifying the exponents:
P(X=14)=54·0.647·0.26.
Calculating the powers:
P(X=14)=54·0.1073741824·0.000064.
Multiplying the values:
P(X=14)=0.109.
Mr Solver

Mr Solver

Skilled2023-05-25Added 147 answers

To solve the given problem, we can use the binomial probability formula. The binomial probability of getting exactly k successes in n independent Bernoulli trials, each with a probability of success p, is given by:
P(X=k)=(nk)·pk·(1p)nk
In this case, we have n=20 people known to have contracted the disease, with a probability of success p=0.8 (since the probability of recovering is 0.8).
We want to find the probability of exactly k=14 people recovering. Plugging these values into the formula, we get:
P(X=14)=(2014)·0.814·(10.8)2014
Now, let's calculate the binomial coefficient (2014), which represents the number of ways to choose 14 successes out of 20 trials. It can be calculated as:
(2014)=20!14!(2014)!
Simplifying this expression, we have:
(2014)=20!14!·6!
Now we can substitute the values into the formula and calculate the probability:
P(X=14)=20!14!·6!·0.814·(10.8)2014
Calculating the value of P(X=14) will give us the likelihood that exactly 14 out of the 20 patients will recover from the stomach disease.
madeleinejames20

madeleinejames20

Skilled2023-05-25Added 165 answers

The binomial distribution formula is given by:
P(X=k)=(nk)·pk·(1p)nk
where:
- P(X=k) is the probability of getting exactly k successes,
- (nk) is the binomial coefficient, representing the number of ways to choose k successes out of n trials,
- p is the probability of success (recovery) in a single trial, and
- (1p) is the probability of failure (not recovering) in a single trial.
In this case, we want to find the probability of exactly 14 recoveries out of 20 patients, where the probability of recovery in a single patient is 0.8. Thus, we have:
P(X=14)=(2014)·0.814·(10.8)2014

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