Answer:
Part 1) The unit rate is 
Part 2) The unit rate is 
Part 3) The unit rate is 
Part 4) The unit rate is 
see the attached figure
Step-by-step explanation:
we know that
The formula to calculate the slope between two points is equal to

where
d ----> number of dollars (dependent variable or output value)
n ---> number of ounces (independent variable or input value)
Remember that the slope of the linear equation is the same that the unit rate
<u><em>Verify each case</em></u>
1) we have

This is a proportional relationship between the variables d and n
The slope is

therefore
The unit rate is 
2) we have
<em>First table</em>
take two points from the table
(4,1) and (16,4)
substitute in the formula of slope



simplify

therefore
The unit rate is 
3) we have

This is a proportional relationship between the variables d and n
isolate the variable d

The slope is

therefore
The unit rate is 
4) we have
<em>Second table</em>
take two points from the table
(1,4) and (2,8)
substitute in the formula of slope



therefore
The unit rate is 