• Welcome! The new FreeMathHelp.com forum is live. We've moved from VB4 to Xenforo 2.1 as our underlying software. Hopefully you find the upgrade to be a positive change. Please feel free to reach out as issues arise -- things will be a little different, and minor issues will no doubt crop up.

Type I Error and Type II Error


New member
Jan 28, 2009
Alpha = P(type I error) = P(reject Ho| Ho true)
Beta = P(type II error) = P(accept Ho| Ho false)

I know what is type of error...
however, when apply to question, i don't really understand how it goes...
For example,

given n=20, Ho : p=0.8, Hi : p<0.8, rejection region = Y<=12
then, i know this step,
Alpha = P(type I error) = P(reject Ho| Ho true) = P(Y<=12 | p=0.8)

but after that, i'm a little bit blur...
what the below step means?

[attachment=0:15152odq]type of error 2.jpg[/attachment:15152odq]

**sorry... i don't know the way to type the symbol here...