The sample proportion is
For example "53 people of the 100 sampled from our population of 1000 voted for candidate 1, thus the sample proportion is 53%" maybe?
Using
Confidence Interval for sample proportions: see CH4B Lecture Notes, Page 44.
Hypothesis Tests of sample proportions: See CH3B Lecture Notes, Page 45
Confidence Intervals for the difference between two proportions: