Question

A researcher developing scanners to search for hidden weapons at airports has

concluded that a new scanner is significantly better than the current scanner. He made his decision based on a test using

alpha equals 0.05

Would he have made the same decision at

alpha equals 0.20 ?

How about

alpha equals 0.001 ?

Explain.

Answer 1

he would have made the same decision at 0.20 level since if a test is significant at 0.05 level therefore p value is less than 0.05 . this indicate that p value should be less than 0.20 as well and therefore test should be significant at 0.20.

we can not know what the decision should be at 0.001 level since knowing that p value is less than 0.05 does not tell us whether p value is less than or greater than 0.001. we can not make any inference at 0.001 level