[On Exams] Problems That Can Be Modeled by Linear Equations
From the
Michael Sullivan Algebra and Trigonometry Textbook Ninth Edition:
https://amzn.to/3DtVB4X
Computing Grades Going into the final exam, which will count as two tests, Brooke has test scores of 80, 83, 71, 61, and 95. What score does Brooke need on the final in order to have an average score of 80?
NOTE* When soling word problems, be very structured and methodic. It will help organize and simplify the process.
Step 1: Isolate any related formulae, definitions, or theorems. [50% of the credit]
Analyze “Computing Grades Going into the final exam, which will count as two tests, Brooke has test scores of 80, 83, 71, 61, and 95. What score does Brooke need on the final in order to have an average score of 80?”
- Read backwards, don’t read left to right—it will confuse you!
- After setting everything up, then go back and read to ensure you are answering correctly.
• average score of 80
• will count as two tests
I read from the end of the question that I need to know average score of 80. Thus, I shall locate a formula for average score of 80. Which is, the sum of the elements divided the total number of elements. I.e.
Definition of Average (or mean)
Example, \(X=\{a,b,c,d\}\)
Note* If you don’t write out the formula, definition, or theorem on an exam, you may not get any credit or lost at least half credit.
Step 2: Formulate [50% of the credit]
Now, 80, 83, 71, 61, 95, and the unknown score can be put into a set,
\(X=\{80,83,71,95,x\}\) and then,
the average,
