Respuesta :
Answer:
0.003 = 0.3% probability that Sarah, Jamal, Kate, and Mai are chosen in any order.
Step-by-step explanation:
The students are chosen without replacement, which means that the hypergeometric distribution is used to solve this question.
Hypergeometric distribution:
The probability of x successes is given by the following formula:
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
In which:
x is the number of successes.
N is the size of the population.
n is the size of the sample.
k is the total number of desired outcomes.
Combinations formula:
[tex]C_{n,x}[/tex] is the number of different combinations of x objects from a set of n elements, given by the following formula.
[tex]C_{n,x} = \frac{n!}{x!(n-x)!}[/tex]
In this question:
11 students means that [tex]N = 11[/tex]
4 are Sarah, Jamal, Kate, and Mai, so [tex]k = 4[/tex]
4 are chosen, which means that [tex]n = 4[/tex]
What is the probability that Sarah, Jamal, Kate, and Mai are chosen in any order?
This is P(X = 4). So
[tex]P(X = x) = h(x,N,n,k) = \frac{C_{k,x}*C_{N-k,n-x}}{C_{N,n}}[/tex]
[tex]P(X = 4) = h(4,11,4,4) = \frac{C_{4,4}*C_{7,0}}{C_{11,4}} = 0.003[/tex]
0.003 = 0.3% probability that Sarah, Jamal, Kate, and Mai are chosen in any order.
