Answer:
The value is 
Step-by-step explanation:
From the question we are told that
The sample size is n = 20
The sample mean is 
The standard deviation is 
Generally the standard error of the mean is mathematically represented as

=> 
=> 
Answer:
"proportional to"
Step-by-step explanation:
The sign ∝ means 'is proportional to'. This is used to show that one variable of value is proportional to another value or variable.
Example:
- x ∝ y ('x' is proportional to 'y')
Hope this helps.
Considering the situation described, the null hypothesis is given as follows:
.
<h3>What are the hypothesis tested?</h3>
At the null hypothesis, it is tested if the <u>mean is the same as in the Census</u>, of $64,000, hence:
.
At the alternative hypothesis, it is tested if the mean is different from the Census, hence:
.
More can be learned about hypothesis tests at brainly.com/question/13873630
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