Answer:
It means that humans lived in that area longer than expected, approximately 28,650 years ago.
Step-by-step explanation:
Ok, this coud be tricky especially taking in count that Radiocarbon dating has other variables that archaeologist take into account so this answer should be taked as an approximation.
Radiocarbon dating measures the amount of carbon-14 (an isotope) in organic objects like bones, plants, wood, charcoal etc...
This is possible because the atmosphere is constantly producing carbon. While a human, animal or tree/plant is alive its amount of carbon is the same as that of the atmosphere. When they die, their amount of carbon kind of "freezes", because it doesnt renew.
Carbon-14 has a peculiarity, every 5730 years its amount in organic objects is cut in half (50%), so for example if the amount of carbon-14 in a dog is 5000 the day it dies, and today the amount found in his skull/bones is 2500, it means that this dog died 5730 years ago.
So for the question:
If a current skull contains a carbon 14 count of 10,000 and the fossil found in the archeological site contains 312.5 we candapproximately find how long ago this human died:
We start by halving 10,000 till we reach the amount found in the skull which is 312.5
We halved 5 times, so we multiply this five times by 5730 and we get 28650
Which means this human died 28650 years ago, and proves that early human settlers lived in that area for longer than we had on record.