A political analyst sampled 8,000 voting records from each of four counties. Of the samples, County A had 5,254 voters who voted in the last election, County B had 4,583, County C had 5,368, and County D had 4,396. The mean from the four counties is 4,900, with a standard deviation of 483. What is the total sample proportion of people who voted in these counties?
0.6125
0.4907
0.4893
0.3875