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Glen_b
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No, $P(X<1)$ is different from $P(|X|<1)$. After all $-2 < 1$ but $|-2|$ isn't!

To get $P(|X|<1)$ you need to find this area:

required area

. . .

While $P(X<1)$ would be this area:

wrong area

Credit: I used the shadenorm function here, which was written by Tony Cookson. It looks like there's a similar function shade.norm in package asbio

Glen_b
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