Jenny Is Testing a Claim About a Population Mean $\mathrm { H } _ { 0 } : \mu = 50$

Essay

Jenny is testing a claim about a population mean. The hypotheses are as follows.
$\mathrm { H } _ { 0 } : \mu = 50$
$\mathrm { H } _ { 1 } : \mu > 50$
She selects a simple random sample and finds that the sample mean is 54.2. She then does some calculations and is able to make the following statement: If H0 were true, the chance that the sample mean would have come out as big ( or bigger) than 54.2 is 0.3. What name is given to the value 0.3? Do you think that she should reject the null hypothesis? Why or why not?