1 When asked to explain the meaning of the Pvalue was P003 a

1. When asked to explain the meaning of \"the P-value was P=0.03,\" a student says, \"This means there is only probability 0.03 that the null hypothesisis true.\" Explain what P = 0.03 really means in a way that makes it clear that the student\'s explanation is wrong.

2. Sketch the standard normal curve for the z test statistic and mark off areas under the curve to show why a value of z that is significant at the 1% level in a one sided test is always significant at the 5% level. If z is significant at the 5% level, what can you say about its significance at the 1% level?

Solution

1.The p value is the probability of obtaining an effect at least as extreme as the one in your sample data, assuming that the null hypothesis true. Now, P=0.03, means if the null hypothesis is true then the observed difference in 3% or more of the study is due to random sampling (error).