CDF to PDF problem (probability)

[asdf12312]

Homework Statement

Homework Equations

integral from -inf to inf of f_x(x)dx = 1, f_x(x)=PMF

The Attempt at a Solution

I get values for probability function PMF of:
0.3, x=0
0.3, x=2
A-0.6, x=3

I guess I try to find area under curve of PMF which will be equal to 1. (0.3)(2) + (1/2)(1)(A-0.6-(0.3))=1 -> A=1.7
Am I doing it right?

 

[rude man]

Homework Statement

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Homework Equations

integral from -inf to inf of f_x(x)dx = 1, f_x(x)=PMF

The Attempt at a Solution

I get values for probability function PMF of:
0.3, x=0
0.3, x=2
A-0.6, x=3

I guess I try to find area under curve of PMF which will be equal to 1. (0.3)(2) + (1/2)(1)(A-0.6-(0.3))=1 -> A=1.7
Am I doing it right?

Don't think so.

(a) what must be the value of F(y) for y → ∞?
(b) since PMF(y) = f(y) = (d/dy)F(y), how must the PMF graph look?
(c) what's the formula for expectation of a distribution f(y)?