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The cdf of $X$ is

$$ F(x) = \cases{0 & $x \leq 0$\\\frac{x}{2} & $0

Find $P(0.5 < X < 1.5)$

I tried solving this problem by solving for $F(1.5)$ and $F(0.5)$ and adding (not subtracting) them.

For $F(1.5)$ I got $43/144$ and for $F(0.5)$ I get $1/16$

When I add them I get $0.36111$.

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    Why don't you subtract them as was your original (correct) intention? – 2017-02-17
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    Sorry about that... I was supposed to add them but I still didn't get the right answer. – 2017-02-17
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    Also $F(1.5)\ne 43/144$ and $f(0.5)\ne 1/16.$ Don't know how you're getting that. Particularly, $F(1/2) = (1/2)/2 = 1/4.$ – 2017-02-17
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    You are supposed to subtract them. (Well technically you are supposed to subtract $F(0.5)$ from $F(1.5^-)$ but $F$ is continuous at $1.5$, so $F(1.5) = F(1.5^-)$) – 2017-02-17
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    Thank you very much! I didn't know what I was thinking. For some reason I did an integration so I got some weird values. All I needed to do was to plug in the numbers directly to the given equations. – 2017-02-17

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