19. Alicia's math quizzes are graded on a scale from 0 to 10. Her average on three quizzes is a 6. Her final math quiz will be counted twice towards her average. What does she need to score on her final quiz in order to raise her average score to a 7? (A) 7 (B) 7.5 (C) 8 (D) 8.5

8.5 cause it is the highest number from the option

  (D) 8.5

Step-by-step explanation:

We can consider the differences from the desired average that Alicia's scores are. She wants an average of 7, but has 3 scores of 6, so is a total of 3(6 -7) = -3 points from her desired average.

If her final quiz counts as two scores, she needs to have a score of x on that which will make her total deviation from average be 0.

  -3 +2(x -7) = 0

  x -7 = 1.5 . . . . . . add 3, divide by 2

  x = 8.5 . . . . . . . add 7

Alicia needs an 8.5 on her final quiz to achieve an average of 7.

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Alternate solution

More conventionally, you would look at the total score Alicia needs. If she wants an average of 7 on 5 quizzes, she needs a total point count of ...

 7 × 5 = 35

Her point count so far is ...

  6 × 3 = 18

So, her final quiz must have an effective point count of ...

  35 -18 = 17

Since it counts as 2 scores, it must be graded as ...

  17/2 = 8.5 . . . score needed on her final quiz

With that score on her final, Alicia's average would be ...

  (6 + 6 + 6 + 8.5 + 8.5)/5 = 35/5 = 7

da freeck kinda math is this just drop out

step-by-step explanation:

mean, 40.6

step-by-step explanation: