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.

i am a little confused myself with what goes with the letters and what goes with the numbers but ill do my best to you

the cordillera states and grand canyon are along the southwest u.s. and northern mexican pacific.

the great plains and southwest desert are also the prairie and home to many earthquakes too .

the coastal plains have poor soil and many factories started in the south.

is this what u needed? if not i can see what i can do