Question 873045
H0 :µ= 530 
H1:µ< 530 

In a random sample of 225 subjects, the sample mean is found to be 
xbar 525 . Also, the population standard deviation is ( 25 ). 

(a) Determine the test statistic. Show all work; writing the correct test statistic, without supporting work, will receive no credit. 

The test statistic is =(525-530)/(25/SQRT(225)) = {{{highlight(-3)}}}


(b) Determine the P-value for this test. Show all work; writing the correct P-value, without supporting work, will receive no credit. 

To get the P-value, enter the following formula in Excel:
=NORMSDIST(-3)
The answer is {{{highlight(0.0013)}}}

(c) Is there sufficient evidence to justify the rejection of 
H0 at the (alpha 0.01) level? Explain

Answer: Since the p-value is less than alpha level, there is sufficient evidence to justify the rejection of {{{H[0]}}}.