Prediction interval, which brackets?

[likearollings]

Prediction interval, which brackets!?

Hi, this is a quick question for a piece of statistics coursework I am doing.

I have made a prediction interval with an upper bound of let's say 30 and lower of 20.

I just don't know which brackets to use open or close e.g.

(20,30)

[20,30]

(20,30]

[20,30)

I know its a bit of a stupid question and is maybe not worthy to be in this forum but I am pretty pedantic when it comes to coursework

Ok any help is appreciated.

 

[Mark44]

Hi, this is a quick question for a piece of statistics coursework I am doing.

I have made a prediction interval with an upper bound of let's say 30 and lower of 20.

I just don't know which brackets to use open or close e.g.

(20,30)

[20,30]

(20,30]

[20,30)

I know its a bit of a stupid question and is maybe not worthy to be in this forum but I am pretty pedantic when it comes to coursework

Ok any help is appreciated.

If we're talking about a continuous distribution as opposed to a discrete distribution, I don't think it makes any difference. Pr(a < X < b) = Pr(a <= X < b) = Pr(a < X <= b) = Pr(a <= X <= b). IOW, the probability that a variable is a single value is zero, so including an endpoint of an interval or omitting it makes no difference.

The only thing I can think of where including/omitting an interval endpoint makes a difference is when your null hypothesis includes the endpoint.

Hope that helps.

 

[likearollings]

Hey thanks,

Yeh it probably doesn't make any difference,

Ill just use the closed brackets as it says on this website

http://www.apastyle.org/learn/faqs/use-brackets.aspx

Thanks