Solve.
-Cindy has scores of $72,84,85$, and 90 on her biology tests. Use a compound inequality to find the range of scores she can make on her final exam to receive a $C$ in the course. The final exam counts as two tests, and a C is received if the final course average is from 70 to 79 .
A) $44.5 \leq$ final score $\leq 71.5$
B) $89 \leq$ final score $\leq 143$
C) $9.5 \leq$ final score $\leq 32$
D) $70 \leq$ final score $\leq 79$

Question

Quizplus · Accepted Answer

To find the range of scores Cindy can make on her final exam to receive a C, we first calculate the total points she has from her current tests: $72 + 84 + 85 + 90 = 331$. Since the final exam counts as two tests, the total number of tests is 6. To get a C, her average needs to be between 70 and 79, so the total points needed for a C are between $70 \times 6 = 420$ and $79 \times 6 = 474$. Subtracting her current total from these bounds gives the range for the final exam: $420 - 331 = 89$ and $474 - 331 = 143$. However, since the final exam counts as two tests, we divide these numbers by 2, resulting in $44.5 \leq$ final score $\leq 71.5$.

Solve -Cindy Has Scores Of 72,84,85 72,84,8572,84,8572,84,85 , and 90 on Her Biology Tests

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-Cindy Has Scores Of 72,84,85 $72,84,85$ , and 90 on Her Biology Tests