1) $f(x) = \begin{cases} \frac{1}{20} \sqrt{x} & x \in [-5,15] \\ 0, & e.o.c. \end{cases}$
2) $f(x) = \begin{cases} \frac{1}{6} \sqrt{x} & x \in [4,10] \\ 0, & e.o.c. \end{cases}$
3) $f(x) = \begin{cases} \frac{1}{5} e^{-\frac{x-8}{5}} & x \ge 8 \\ 0, & e.o.c. \end{cases}$
4) $f(x) = \begin{cases} \frac{1}{10} e^{-\frac{x}{10}} & x \ge 0 \\ 0, & e.o.c. \end{cases}$
For all distributions above:
a) Prove that f(x) is a probability distribution (that is:
f(x) is always more than or equal to zero, and
that the sum of all probabilities = 1)
b) Find F(x)
c) Find $Pr[X \ge 9]$
d) Find $Pr[X \in [8,10]]$
e) Find $F^{-1}(q)$
f) Estimate the value of x such that the value of F(x)
= 0.3
g) Find the critical values of x such that 2.5% of
probability lies to the right of x
h) Find E(X)
i) Find Var(X) and Stdev(X)