# Math Help - AP stats

1. ## AP stats

When testing hypotheses, im having a hard time with the conclusion.
I can get the p-value, but my book says if you have a low pvalue, you reject the null. For example,

Trying to see if there is a homefield advantage..
Ho : p=0.50
Ha : p>0.50

P value < 0.0001
If the true proportion of home team wins were .50, then the observed value of .5496 would occur .0001
My book says since it is so low, you reject Ho.
This seems backwards to me, can someone explain?

2. Originally Posted by Morgan82
When testing hypotheses, im having a hard time with the conclusion.
I can get the p-value, but my book says if you have a low pvalue, you reject the null. For example,

Trying to see if there is a homefield advantage..
Ho : p=0.50
Ha : p>0.50

P value < 0.0001
If the true proportion of home team wins were .50, then the observed value of .5496 would occur .0001
My book says since it is so low, you reject Ho.
This seems backwards to me, can someone explain?
No its not, what the p value means is that the probability of getting an observed value as high as 0.5496 or higher by chance if Ho holds is 0.0001.

So that this value occured given that Ho holds is very unlikely so we reject Ho.

RonL