Answer:
0.43 is the required probability.
Explanation:
We are given the following in the question:
Number of participants that prefer Ad A = 54
Number of participants that prefer Ad B = 86
Number of participants that prefer Ad C = 60
Total number of participants =

We have to find the proportion of participants preferring Ad B.
Proportion =

Thus, 0.43 is the proportion of participants preferring Ad B.