Given :- 50% of all voters are democrats.
Probability that randomly selected voter will be a democrat = 0.50.
Independent event Property :- If two events A and B are independent on each other then P(A and B) = P(A) * P(B).
In this question, Vote of one person is independent on another person. Every individual's vote preference is independent.
The probability that they are both democrats
= P( first is democrat AND second is also a democrat)
=P(first is democrat) * P(second is also a democrat)
= 0.50 * 0.50 (Using above property of independent events)
= 0.25
Answer :- If two voters are randomly selected for a survey, Then the probability that they are both democrats is 0.25.