**19. Correct. The answer is
true.**

(a) Since all values of z > 3 have probability zero, we take as the *maximum* value z = 3. Likewise, since all
values of z < 0 have probability zero, we take as the *minimum* value z = 0. Then, the range is 3 - 0 = 0.

(b) In problem 17, we calculated the 25%-ile and 75%-ile in 1.098 and
2.121 respectively. The semi- interquartile range is
equal to (1.098 - 2.121)/2 ≈ 0.51 (US$ 510).

(c) From problem 16, the mean of the density function is μ = 1.60 =
8/5. Then, the mean deviation is:

_{}

Decomposing the integral due to the absolute value in the integrant:

_{}

(US$ 560)