Hannah, this is the solution:
Step 1: We need to add up the number of voters and the number of registered voters that did not vote.
In consequence,
3'121,201 + 3'349,227 = 6'470,428 registered voters
Step 2: Now we need to calculate the percentage of registered voters that did not vote, as follows:
3'349,227 / 6'470,428 = 0.5176
0.5176 = 51.76%
Step 3: Now we will round to three decimal places, this way:
0.5176 = 0.518 (rounding to three decimal places)
0.518 = 51.8%
Step 4: The answer will be that the probability that a registered voter did not vote in the election is approximately 51.8%