Answer:
E(X)= 3.029
Explanation:
Hello!
The variable of interest is
X: The number of first-generation college students in a sample of 13 college students.
The population proportion of the freshmen that are first-generation college student is 23.3%
This variable is discrete.
Considering the binomial criteria:
1. The number of observations of the trial is fixed, each repetition has two possible outcomes, "success": the student is first-generation college student, or "failure": the student isn't a first-generation college student.
2. Each observation in the trial is independent, this means that none of the trials will affect the probability of the next trial
3. The probability of success in the same from one trial to another
So X≈ Bi (n;ρ)
n= 13 p=0.233
For the binomial distribution the expected value is:
E(X)= n*p= 13*0.233= 3.029.
I hope it helps!