Total number of people in the district is 9570. The candidate took a phone poll of 110 people. The proportion of the total number people in the district that participated in the phone poll is 9570/110 = 87
This means that the total number of people in the district is 87 times the number that participated in the phone poll
If out of 110 people polled, 87 said they would vote for the other person, the number of people that would vote for the other person will be 87×87 = 7569
