The probability \( P(1 \leq X \leq 2) \) is found by integrating the probability density function \( p(x) \) over the range from 1 to 2:
\[
P(1 \leq X \leq 2) = \int_1^2 2e^{-2x} \, dx.
\]
To solve the integral:
\[
\int 2e^{-2x} \, dx = -e^{-2x}.
\]
Now, evaluate the integral from 1 to 2:
\[
P(1 \leq X \leq 2) = \left[ -e^{-2x} \right]_1^2 = -e^{-4} + e^{-2}.
\]
Substitute the values of \( e^{-4} \) and \( e^{-2} \):
\[
P(1 \leq X \leq 2) = -(0.0183) + (0.1353) = 0.1170.
\]
Thus, the probability is approximately 0.11.