10 questions · Form 5 Mathematics Bab 7: Measures of Dispersion for Grouped Data
Calculate the class size for the class interval 15 - 19.
Prefer reading to quizzing? All 10 questions are listed below with the answer and explanation under each one.
1. Calculate the class size for the class interval 15 - 19.
Answer: A
Lower boundary = 14.5, Upper boundary = 19.5. Class size = 19.5 - 14.5 = 5.
2. The Modal Class in a grouped frequency table is the class interval with the:
Answer: A
The modal class is the class interval containing the maximum frequency.
3. Using ∑f = 50, ∑fx = 300, and ∑fx² = 2300, find the variance σ².
Answer: A
Variance σ² = (∑fx² / ∑f) - (x̄)² = (230050) - 6² = 46 - 36 = 10.
4. What is the standard deviation σ for a dataset with a variance of 16?
Answer: A
Standard deviation σ = √(Variance) = √16 = 4.
5. What is the midpoint of the class interval 40 - 48?
Answer: A
Midpoint x = Lower limit + Upper limit2 = 40 + 482 = 44.
6. In a grouped data table with class intervals 10-14, 15-19, 20-24, what is the lower boundary of the starting point on an ogive?
Answer: B
An ogive starts at cumulative frequency 0 at the lower boundary of the first class interval (10 - 0.5 = 9.5).
7. Which measure of dispersion is affected by every score in a grouped dataset and measured in squared units?
Answer: B
Variance measures the mean of squared deviations from the mean and is expressed in square units.
8. When constructing a frequency polygon directly from a histogram, line segments connect:
Answer: A
A frequency polygon connects the midpoints of the top edges of histogram bars.
9. For N = 200, the first quartile Q₁ occurs at a cumulative frequency of:
Answer: C
Position of Q₁ = (14) × 200 = 50.
10. If total frequency N = 80, at what cumulative frequency do you locate the third quartile (Q₃) on an ogive?
Answer: C
Q₃ corresponds to (34) × N = (34) × 80 = 60.