Answer: The answer is 68.574961%.
Step-by-step explanation: Given in the question that there is a 9% chance that a booked gig will get cancelled. We have 4 gigs in a row and we need to find the probability that none of them will get cancelled.
The probability of a gig not get cancelled will be
[tex]p_g=1-0.09=0.91.[/tex]
Since the chances of being cancelled for the 4 gigs are independent events, so the probability that none of the 4 gigs are cancelled is
[tex]P=0.91\times 0.91\times 0.91\times 0.91=0.68574961.[/tex]
Thus, the required probability is 68.574961%.