SOLUTION: On a 50 question true-false test, a student received 3 points for each correct answer. For each incorrect answer, the student lost 1 point. For an unanswered question, no points we

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Question 105552This question is from textbook Algebra and Trigonometry
: On a 50 question true-false test, a student received 3 points for each correct answer. For each incorrect answer, the student lost 1 point. For an unanswered question, no points were added or deducted.
a) find best score possible
b) find worst score possible
c) find the linear function that converts the raw score described above to a score from 0 to 100
d) What score from 0 to 100 corresponds to a test result of 38 correct, 4 incorrect, and 8 omitted.
This question is from textbook Algebra and Trigonometry

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
The students are only scored on the questions they answer.
(a) The best score would be 50 questioned all answered correctly
3%2A50+=+150 answer
(b) The worst score would be 50 qestions all answered incorrectly
-1%2A50+=+-50
(c) The raw score would be 3%2AC+-+%28A+-+C%29, where
A = the number of questions answered, and
C = the number of questions answered correctly
I want the worst score of -50 to correspond to 0
I want the best score of 150 to correspond to 100
For the worst score to equal 0, I need to add 50, so I have
3C+-+%28A+-+C%29+%2B+50
3%2A0+-+%2850+-+0%29+%2B+50+=+0 this is true
Now I have to make the best score = 100
k%283%2A50+-+%2850+-+50%29%29+%2B+50+=+100
k%28150+-+50+%2B+50%29+%2B+50+=+100
solve for k
150k+=+50
k+=+1%2F3
So the score is 1%2F3%2A%283C+-+%28A+-+C%29%29+%2B+50
(d)C = 38
I = 4
A = 50 - 8 = 42
1%2F3%2A%283C+-+%28A+-+C%29%29+%2B+50
1%2F3%2A%283%2A38+-+%2842+-+38%29%29+%2B+50
1%2F3%2A%28114+-+4%29+%2B+50
1%2F3%2A110+%2B+50+=+86.66 answer