Answer:
D. R(x) = 850x +9600
Detailed explanation:
Selling 10 additional machines increased revenue from $18100 to $26600, which reflects an increase of...
... $26,600 minus $18,100 equals $8,500
This indicates that revenue rose by $8500 divided by 10, which equals $850 per machine.
Only one option contains this value:
... D. R(x) = 850x+9600
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Verification
R(10) = 850·10 +9600 = 8500 +9600 = 18,100.... Correct
R(20) = 850·20 +9600 = 17000 +9600 = 26,600.... Correct
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Comments on choice selection
In multiple-choice scenarios, it's often not required to solve the entire problem accurately. Generally, it's enough to identify the single number that distinguishes the correct from the incorrect options.
In reality, problems are seldom multiple-choice. One must go through the process thoroughly and determine whether the answer is accurate.
Here, we delved deep enough to find the slope, representing the revenue gain when one unit increase in sales occurs. Different methods can determine the intercept. One such method is to identify the value that aligns revenue with one of the "x" values:
... R(10) = 850·10 +b = 18100
... b = 18100 -8500 = 9600
therefore...
... R(x) = 850x +9600
We can verify this answer by calculating R(20) as shown previously.
