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# P(3 <=x <7) = p (x <=6) - p (x <=3)?? watch

1. Was doing some poison questions

For what i put in the title.

I understand that x should habe values at 3 4 5 6.

What i dont get is how you rearrange the inequality so P (3 <=X) = P (X>=3) = 1 - P (X <=2)

But this does not seem correct in the concept of the question.

TeeEm
2. Can you clairfy your question? What exactly are you trying to ask? I'm a little lost.
3. (Original post by Mihael_Keehl)
Was doing some poison questions

For what i put in the title.

I understand that x should habe values at 3 4 5 6.

What i dont get is how you rearrange the inequality so P (3 <=X) = P (X>=3) = 1 - P (X <=2)

But this does not seem correct in the concept of the question.

TeeEm
I am teaching at present ...
4. P(3<=X) is exactly the same as P(X>=3) just FYI.Now what that means is that it's asking you for the probability that X is equal to or greater than 3. Now the table in the back tells you P(X<=x), so you need to change from P(X>=3) to make it X is less than something. The table tells you the combined probability of all the numbers leading up to and including x. If you think about the sum of all the probabilities, the answer is 1. So if P(X>=3)+P(X<=x)=1 and P(X>=3) includes all the values of 3 and up, what would x be to make P(X>=3)+P(X<=x) = 1
5. (Original post by Zacken)
Can you clairfy your question? What exactly are you trying to ask? I'm a little lost.
I was on my phone in the OP. In trying to elucidate it, what I meant was that:

P(3 <=x <7) = p (x <=6) - p (x <=2) from my book.

I do not understand how one derives the p (x <=2) part.

From the range, x must be equal to values; 3 4 5 and 6.

However P(3 <=x <7) = P(X<=6) - (1-P(x>=3) = P(X<=6) - (1-1 -p(X<=2) = P(x<=6) + P(X<=2)

How are you supposed to derive the - p (x <=2) was what I was trying to convey :l

(Original post by TeeEm)
I am teaching at present ...
:/
(Original post by NinjaOtter)
P(3<=X) is exactly the same as P(X>=3) just FYI.Now what that means is that it's asking you for the probability that X is equal to or greater than 3. Now the table in the back tells you P(X<=x), so you need to change from P(X>=3) to make it X is less than something. The table tells you the combined probability of all the numbers leading up to and including x. If you think about the sum of all the probabilities, the answer is 1. So if P(X>=3)+P(X<=x)=1 and P(X>=3) includes all the values of 3 and up, what would x be to make P(X>=3)+P(X<=x) = 1
Your answer to that would be 1 - P(x>=3) = 1-( 1- P(X<3) = 1 - ( 1 - P(x<=2) = P(X<=2) is it that right.

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