Answer:
average rate of change = 12
Explanation:
the average rate of change of f(x) in the interval a ≤ x ≤ b is

here the interval is 2 ≤ x ≤ 4 , then
f(b) = f(4) = 2(4)² - 2 = 2(16) - 2 = 32 - 2 = 30
f(a) = 2(2)² - 2 = 2(4) - 2 = 8 - 2 = 6
then
average rate of change =
=
= 12