# what does this mean?Watch

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Thread starter 14 years ago
#1
P(|X-16|<3)?

How would you change this so you could solve the probability? I dont really understand the modulus function. Can anyone explain this to me?

Thanks
0
14 years ago
#2
(Original post by annabelle)
P(|X-16|<3)?

How would you change this so you could solve the probability? I dont really understand the modulus function. Can anyone explain this to me?

Thanks
The modulus function means that whatever is within the function, the sign is just made positive.

I find the best way to approach them is to consider it when (in your case)
x-16 is +ve, in which case you can ignore the modulus and seperately when x-16 is -ve, i.e. it is effectively 16-x.
0
Thread starter 14 years ago
#3
(Original post by lgs98jonee)
The modulus function means that whatever is within the function, the sign is just made positive.

I find the best way to approach them is to consider it when (in your case)
x-16 is +ve, in which case you can ignore the modulus and seperately when x-16 is -ve, i.e. it is effectively 16-x.
So does that mean P(|X-16|<3) = P(X<13)?
0
14 years ago
#4
|X-16|<3

X-16<3 ... X < 19
or
16-X<3 X > 13

=13<X<19
0
14 years ago
#5
Generally

|x-a|<b

is the same as the inequality

a-b < x < a+b.

Think of |x-a| as the distance of x from a (or vice versa).

In probability it's important as you might need to know

P(|x-mu| < sigma)

the probability of being within one standard deviation of the mean.
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Thread starter 14 years ago
#6
ohhh i see! Thanks!
0
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