Answer:
z=3.8196
Step-by-step explanation:
-We notice that this is a normal distribution problem.
-Given the mean is $8500, standard deviation is $1200 , and n=350, the critical z-value using alpha=0.05 is calculated as:
[tex]z=\frac{x-\mu_o}{\sigma/\sqrt{n}}\\\\=\frac{8745-8500}{1200\sqrt{350}}\\\\\\=3.8196[/tex]
Hence, the test statitic is z=3.8196