Question

explain in general how a p-value is computed.

Answer 1

Ans:

The P value, or calculated probability, is the probability of finding the observed, or more extreme, results when the null hypothesis (H ₀) of a study question is true – the definition of 'extreme' depends on how the hypothesis is being tested.

We use population parameters and sample statistics to calculate the test statistic.

e.g. one sample mean test

For testing if

sample mean=9.5,

population mean=10

population standard deviation=2

n=16

Test statistic:

z=(9.5-10)/(2/sqrt(16))

z=-1

p-value=P(z<-1)=0.1587