Respuesta :
Answer:
The formula to compute the probability that at exactly x of the students scored over 650 points is:
[tex]P(X=x)={9\choose x}\ (0.30)^{x}\ (1-0.30)^{9-x}[/tex]
Step-by-step explanation:
Let the random variable X represent the number of students who scored above 650 in the college entrance exam.
The probability that a student scored above 650 in the college entrance exam is, p = 0.30.
A random sample of n = 9 students was selected.
The events of any student scoring above 650 in the college entrance exam is independent of the others.
The random variable X follows a Binomial distribution with parameters n = 9 and p = 0.30.
The probability mass function of X is:
[tex]P(X=x)={9\choose x}\ (0.30)^{x}\ (1-0.30)^{9-x};\ x=0,1,2,3...[/tex]
Thus, the formula to compute the probability that at exactly x of the students scored over 650 points is:
[tex]P(X=x)={9\choose x}\ (0.30)^{x}\ (1-0.30)^{9-x}[/tex]
