Answer:
The decision rule is
Reject the null hypothesis
Step-by-step explanation:
From the question we are told that
The population mean is 
The sample size is n = 160
The sample mean is 
The variance is 
The level of significance is 
The null hypothesis is 
The alternative hypothesis is 
Generally the standard deviation is mathematically represented as

=>
=>
Generally the test statistics is mathematically represented as

=>
=> 
From the z table the area under the normal curve to the left corresponding to 2.53 is

From the value obtained we see that the
hence
The decision rule is
Reject the null hypothesis
The conclusion is
There is sufficient evidence to conclude that the believe that the valve performs above the specifications is true
Answer:
C) Casey is incorrect because more than one student can have the same GPA.
Step-by-step explanation:
This is not necessarily true. There are multiple people that will have the exact same Grade Point Average. It is a big school, and some people do as good as others.
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