You are testing the null hypothesis that 0 versus the alte

You are testing the null hypothesis that ? = 0 versus the alternative ? > 0 using ? = .05. Assume ? = 21. Suppose x = 5.5 and n = 20. Calculate the test statistic and its P-value. Repeat assuming the same value of x but with n = 30.

n=20 z=______ p-value= _______

n=30 z= ______ p-value= _______

Solution

n=20:

Z=(xbar-mu)/(s/vn)

=(5.5-0)/(21/sqrt(20))

=1.17

It is a right-tailed test.

So the p-value= P(Z>1.17) =0.1210 (from standard normal table)

---------------------------------------------------------------------------------------------

n=30:

Z=(xbar-mu)/(s/vn)

=(5.5-0)/(21/sqrt(30))

=1.43

It is a right-tailed test.

So the p-value= P(Z>1.43) =0.0764 (from standard normal table)