Answer:
54.17%
Explanation:
The probability of a person receiving the treatment experiencing significant side effects is calculated by dividing the number of people who experienced significant side effects by the total number of participants. Since 55 out of 120 participants experienced no significant side effects, then 120 - 55 = 65 participants experienced significant side effects. Therefore, the probability of a person receiving the treatment experiencing significant side effects is 65/120 = 0.54 or 54%.