Answer:
Thus, the pmf of the number of granite specimens selected for analysis is [tex]P(X=x)={20\choose x}0.50^{x}(1-0.50)^{20-x}[/tex].
Step-by-step explanation:
The experiment consists of collecting rocks.
The sample consisted of, 10 specimens of basaltic rock and 10 specimens of granite.
The total sample is of size, n = 20.
Let the random variable X be defined as the number of granite specimen selected.
The probability of selecting a granite specimen is:
[tex]P(Granite)=p=\frac{10}{20}=0.50[/tex]
A randomly selected rock can either be basaltic or granite, independently.
The success is defined as the selection of granite rock.
The random variable X follows a Binomial distribution with parameter n = 20 and p = 0.50.
The probability mass function of X is:
[tex]P(X=x)={20\choose x}0.50^{x}(1-0.50)^{20-x}[/tex]
