\textbf{Binomial distribution with parameters n = 8 and p = 0.20.}  \textbf{$$P(X = 3) ={8 \choose 3}(0.20)^{3}(0.80)^{5}$$} 
\textbf{In a population of university students, 20\% of the students have experienced feelings of math anxiety. If we select 8 students, what is the probability that exactly three have experienced math anxiety?} 
1: $${8 \choose 3} (0.20)^{3} (0.80)^{8}$$ 
2: $${8 \choose 3} (0.20)^{3} (0.80)^{5}$$ 
3: $${5 \choose 3} (0.20)^{3} (0.80)^{5}$$ 
4: $$(0.20)^{3} (0.80)^{5}$$ 
5: $$(0.20)^{5} (0.80)^{3}$$ 