Answer:
The value of the test statistic is [tex]z = -1.5[/tex]
Step-by-step explanation:
The formula for the test statistic is:
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
In which X is the statistic, [tex]\mu[/tex] is the mean, [tex]\sigma[/tex] is the standard deviation and n is the number of observations.
In this problem, we have that:
[tex]\mu = 20, X = 17, \sigma = 6, n = 9[/tex]
So
[tex]z = \frac{X - \mu}{\frac{\sigma}{\sqrt{n}}}[/tex]
[tex]z = \frac{17 - 20}{\frac{6}{\sqrt{3}}}[/tex]
[tex]z = -1.5[/tex]
The value of the test statistic is [tex]z = -1.5[/tex]
