Answer: -0.87
Step-by-step explanation:
As per given , we have
[tex]\mu=3[/tex]
[tex]\overline{x}=2.9\\\\ \sigma=0.5[/tex]
Sample size : n= 19
Test statistic : [tex]z=\dfrac{\overline{x}-\mu}{\dfrac{\sigma}{\sqrt{n}}}[/tex]
By substituting the corresponding values , we get
[tex]z=\dfrac{2.9-3}{\dfrac{0.5}{\sqrt{19}}}\\\\=-0.871779788708\approx0.87[/tex] [Rounded to the nearest two decimal places.]
Hence, the test statistic (z-score) of this one-mean hypothesis test= -0.87