What percentage of geologic time is represented by recorded history? (Assume 5000 years for the length of recorded history.)

only about 20% - 35%

Explanation:

We do not know that much about the earth itself, and people just recently started discovering the earth for what it truly is. Though, we have been recording earthquakes and tsunamis since the early 19th century.

This makes up anywhere from 20% to 35%. It is hard to know the exact percentage for sure.

5.4%

explanation:

the acceptance rate for harvard is 5.4%. this means only 5 percent of people who apply actually get accepted!