Convection currents in the magma drive plate tectonics. Heat generated from the radioactive decay of elements deep in the interior of the Earth creates magma (molten rock) in the aesthenosphere. Theaesthenosphere (70 ~ 250 km) is part of the mantle, the middle sphere of the Earth that extends to 2900 km.
Answer:
21.65
Explanation:
The average = total divided by the number of readings
21.57
22.04
<u>21.35</u>
Total = 64.96
Average = 64.96 / 3 = 21.65
-2 cuz 20 negative minus 18 positive is -2
