QuestionAugust 26, 2025

GRADES On her first four quizzes, Rachael has earned scores of 21,24,23, and 17 points. What score must Rachael earn on her fifth and final quiz so that both the mean and median of her quiz scores is 21? square

GRADES On her first four quizzes, Rachael has earned scores of 21,24,23, and 17 points. What score must Rachael earn on her fifth and final quiz so that both the mean and median of her quiz scores is 21? square
GRADES On her first four quizzes, Rachael has earned scores of 21,24,23, and 17
points. What score must Rachael earn on her fifth and final quiz so that both the
mean and median of her quiz scores is 21?
square

Solution
4.5(218 votes)

Answer

20 Explanation 1. Calculate the Required Mean The mean of five scores must be 21. Therefore, the total sum of scores should be 5 \times 21 = 105. 2. Calculate Current Total Current total is 21 + 24 + 23 + 17 = 85. 3. Determine Required Score for Fifth Quiz Let the fifth score be x. Then, 85 + x = 105. Solving gives x = 20. 4. Verify Median Condition Arrange scores with x=20: 17, 20, 21, 23, 24. The median is 21, satisfying the condition.

Explanation

1. Calculate the Required Mean<br /> The mean of five scores must be 21. Therefore, the total sum of scores should be $5 \times 21 = 105$.<br />2. Calculate Current Total<br /> Current total is $21 + 24 + 23 + 17 = 85$.<br />3. Determine Required Score for Fifth Quiz<br /> Let the fifth score be $x$. Then, $85 + x = 105$. Solving gives $x = 20$.<br />4. Verify Median Condition<br /> Arrange scores with $x=20$: $17, 20, 21, 23, 24$. The median is 21, satisfying the condition.
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