This is a proportion. First you take the numerator times the denominator that is already solved. In this case you will take 5 times 7 and get 35. You then take 35 divided by 4 and get your answer.
The probability that none of the four have been vaccinated is
(1-0.63)^4 = 0.01874161
The probability that at least one has been vaccinated is the complement of this,
≈0.9813
Answer:
0. 542
Step-by-step explanation: