Answer:
The probability is:
0.087723
Explanation:
We need to use the binomial distribution to calculate the probability.
We are given that:
The probability that a tennis set will go to a tie-breaker is 19%.
i.e. the probability is: 0.19
Also, we are asked to find the probability that two of three sets will go to tie-breakers.
We know that the probability of binomial distribution is given as:

where n are the total outcomes.
p is the probability of success.
and P denotes the probability.
Here we have:
p=0.19
k=2
and n=3
Hence,

Hence, the probability that two of three sets will go a tie breaker is:
0.087723