Answer: -1.55
Step-by-step explanation:
Given : Mean : [tex]\mu=100[/tex]
Standard deviation : [tex]\sigma=20[/tex]
Sample size : [tex]n=60[/tex]
Sample mean : [tex]\overline{x}=96[/tex]
The test statistic for the population mean is given by :-
[tex]z=\dfrac{\overline{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]
[tex]\Rightarrow\ z=\dfrac{96-100}{\dfrac{20}{\sqrt{60}}}=-1.54919333848\approx-1.55[/tex]
Hence, the value of z statistic = -1.55
