Grade 10 Math: Data Management Quiz
Measures of Central Tendency & Spread
1. A student records their math quiz scores out of 10: 6, 8, 7, 9, 8, 10, 6, 8. What is the mode of these scores?
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Formula: Mode = The value that occurs most frequently
Brief Solution: Count the frequency of each number. 6 appears twice, 7 appears once, 8 appears three times, 9 appears once, and 10 appears once. Correct Answer: B (8)
2. Find the median of the following set of daily high temperatures (in Celsius): -3, 2, -1, 5, 0, 4, -2.
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Formula: Median = The middle value when data is arranged in order
Brief Solution:
1. Arrange the data from least to greatest: -3, -2, -1, 0, 2, 4, 5.2. Locate the middle position. Since there are 7 data points (an odd number), the 4th position is the exact middle.
Correct Answer: C (0 °C)
3. Consider the following table showing the number of goals scored by a hockey team over 6 games:
| Game | Goals Scored |
|---|---|
| 1 | 2 |
| 2 | 5 |
| 3 | 1 |
| 4 | 4 |
| 5 | 3 |
| 6 | 3 |
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Formula: Mean = (Sum of all values) ÷ (Total number of data points)
Brief Solution: 1. Sum = 2 + 5 + 1 + 4 + 3 + 3 = 18
2. Total games (n) = 6
3. Mean = 18 ÷ 6 = 3.0
Correct Answer: A (3.0)
4. The range of a set of data is 24. If the lowest value (minimum) in the dataset is 11, what is the highest value (maximum)?
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Formula: Range = Maximum value - Minimum value
Brief Solution: Rearrange the formula to solve for the Maximum:Maximum = Range + Minimum
Maximum = 24 + 11 = 35
Correct Answer: C (35)
5. A local coffee shop tracks the number of espresso shots added to specialty drinks over an hour:
| Shots Added (x) | Frequency (f) |
|---|---|
| 1 | 5 |
| 2 | 12 |
| 3 | 4 |
| 4 | 2 |
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Formula: Mode = The data value with the highest frequency
Brief Solution: Look down the "Frequency" column to find the highest number, which is 12. The corresponding data value in the "Shots Added" column is 2.Correct Answer: A (2)
6. An even number of data points are already arranged in order: 12, 15, 17, 21, 25, 30. How do you calculate the median?
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Formula: Median (for even n) = (Sum of the two middle values) ÷ 2
Brief Solution: There are 6 items. The two middle values are the 3rd and 4th terms, which are 17 and 21. You must average them: (17 + 21) ÷ 2 = 19.Correct Answer: D (Find the mean of 17 and 21.)
7. A small retail business has five employees who earn hourly wages of $16, $16, $18, $20, and $45. Which measure of central tendency is distorted the most by the $45 outlier?
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Concept: The Mean is sensitive to outliers because it incorporates every exact value.
Brief Solution: - Without $45, the mean is $17.50. With $45, it jumps to $23.00 (higher than what 4 out of 5 people make).
- The median remains $18 and the mode remains $16 regardless of the outlier value.
Correct Answer: C (Mean)
8. A teacher organizes the class project percentages into a frequency table:
| Mark (%) | Number of Students (f) |
|---|---|
| 65 | 3 |
| 75 | 7 |
| 85 | 8 |
| 95 | 2 |
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Formula: n = Σf (Sum of all frequencies)
Brief Solution: Add up the number of students in each category to find the total sample size: 3 + 7 + 8 + 2 = 20.Correct Answer: B (20)
9. A set of four numbers has a mean of 10. If three of the numbers are 8, 11, and 12, what is the fourth number?
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Formula: Required Total Sum = Mean × n
Brief Solution: 1. Calculate required total sum: 10 × 4 = 40
2. Sum the known numbers: 8 + 11 + 12 = 31
3. Subtract to find the missing number: 40 - 31 = 9.
Correct Answer: B (9)
10. You are given the dataset: 5, 5, 7, 8, 10. If a new number, 15, is added to this dataset, which of the following statements is true?
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Formula: Range = Maximum - Minimum
Brief Solution: - Original Range: 10 - 5 = 5
- New Range (with 15 included): 15 - 5 = 10.
Since the new value is higher than the previous maximum, the gap between the largest and smallest numbers expands.
Correct Answer: C (The range increases.)
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