5. Correct. The answer is true.

a) We have to derive the cummulative probability function so as to obtain the density function (it is an application of the fundamental theorem of calculus):

b) By definition of the complement of a probability P(x ≤ 2 ) = 1 - P(x >2 ):

P(x>2) = 1 - (1-e^-4) = e^-4 ≈ 1.83%

c) P(2 ≤ x ≤ 4) = P( x ≤ 4) - P( x ≤ 2) = F(4) - F(2) ≈ 1.79%