Answer:
The test statistics is [tex]z = 2.47[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is n = 191 \ buses
The sample mean is [tex]\= x = 96 700 \ miles[/tex]
The population standard deviation is [tex]\sigma = 37 500 \ miles[/tex]
The null hypothesis is [tex]H_o : \mu = 90 000[/tex]
The alternative hypothesis is [tex]H_a : \mu > 90 000[/tex]
Generally the test statistics is mathematically represented as
[tex]z = \frac{\= x - \mu }{ \frac{\sigma }{\sqrt{n} } }[/tex]
=> [tex]z = \frac{96700 - 90 000 }{ \frac{37500}{\sqrt{191} } }[/tex]
=> [tex]z = 2.47[/tex]
