Answer:
a) 0.905 (3 dp)
Step-by-step explanation:
Binomial distribution X ~ B(n, p)
where n is the the number of trials and p is the probability of success
Binomial formula:
[tex]P(X=x)=\left(\left\begin{array}{cc}n\\x\end{array}\right) \cdot p^x \cdot (1-p)^{n-x}[/tex]
Given: X ~ B(100, 0.001)
Therefore, n = 100 and p = 0.001
Substituting these values into the binomial formula and solving for x = 0:
[tex]\implies P(X=0)=\dfrac{100!}{0!100!} \cdot 0.001^0 \cdot (1-0.001)^{100-0}[/tex]
[tex]\implies P(X=0)=1 \cdot 1 \cdot 0.999^{100}[/tex]
[tex]\implies P(X=0)=0.9047921471...[/tex]
[tex]\implies P(X=0)=0.905 \ \sf(3 \ dp)[/tex]