Answer:
0.0537
Step-by-step explanation:
This follows a binomial distribution with : n
Number of trials 'N' = 12 ; Probability of success (difference between speakers) 'p' = 1/2 or 0.5 ; Probability of failure (no difference b/w speakers) = 1/2 or 0.5 ; No of success 'r' = 3
P (X = 3) = [tex]N C r. (p)^r.(q)^(n-r)\\[/tex]
= 12C3 (0.5)^3 (0.5)^9
0.0537
