Whats the decimal of a ratio of 1: 3

Stone mountain was formed during the formation of the blue ridge mountains around 300-350 million years ago and is considered part of the appalachian mountains. it formed as a result of the upwelling of magma from within the earth's crust. this upwelling, or solidified to form the that became stone mountain.

What was the great rift valley formed by

Mexico city is an example of how humans alter their environment because it was a. one of the world’s largest cities b. built on drained and filled lake beds c. built after conquest by the spanish d. once the capital of the aztec empire