TERM: 2ND TERM
WEEK 11
Class: Senior Secondary School 1
Age: 15 years
Duration: 40 minutes of 4 periods
Subject: Further Mathematics
Topic: Measure of Dispersion
Focus: Mean Deviation, Standard Deviation, Coefficient of Variation
SPECIFIC OBJECTIVES:
By the end of the lesson, students should be able to:
- Understand and calculate the mean deviation of a data set.
- Compute the standard deviation for a data set.
- Calculate the coefficient of variation and understand its significance.
INSTRUCTIONAL TECHNIQUES:
- Question and answer
- Guided demonstration
- Group discussion
- Practice exercises
- Real-life application of measures of dispersion
INSTRUCTIONAL MATERIALS:
- Whiteboard and markers
- Charts illustrating measures of dispersion
- Flashcards with examples of data sets for calculation
- Calculators for practice
- Worksheets for exercises
PERIOD 1 & 2: Introduction to Measures of Dispersion
PRESENTATION:

4. What is the significance of the coefficient of variation in comparing two data sets?
5. What does a larger standard deviation indicate about a data set?
CLASSWORK (5 questions):
- Calculate the mean deviation for the data set: [3, 5, 8, 10, 15].
- Find the standard deviation for the data set: [10, 20, 30, 40].
- Calculate the coefficient of variation for a data set with a mean of 50 and a standard deviation of 10.
- What is the relationship between standard deviation and variance?
- For which type of data would the coefficient of variation be most useful?
ASSIGNMENT (5 tasks):
- Find the mean deviation for the data set: [5, 7, 9, 14, 16].
- Calculate the standard deviation for the data set: [4, 6, 8, 10, 12].
- Compute the coefficient of variation for a data set with a mean of 30 and a standard deviation of 8.
- Identify one real-life application where mean deviation is used.
- Find the standard deviation of the following data set: [18, 25, 32, 40, 50].
PERIOD 3 & 4: Application and Practice
PRESENTATION:
Step
|
Teacher’s Activity
|
Student’s Activity
|
Step 1 - Review of Previous Work
|
Recaps the calculations of mean deviation, standard deviation, and coefficient of variation. Reviews any common errors from the previous periods.
|
Students review their notes and ask for clarification on any points they found difficult.
|
Step 2 - Guided Practice
|
Provides more complex data sets for students to calculate the measures of dispersion. Demonstrates how to work through problems that involve multiple data sets.
|
Students work in pairs or groups to calculate the measures of dispersion for the given data sets.
|
Step 3 - Independent Practice
|
Assigns additional data sets for students to calculate the mean deviation, standard deviation, and coefficient of variation on their own.
|
Students work independently, using calculators and their notes to complete the task.
|
Step 4 - Real-life Connections
|
Provides examples of how measures of dispersion are used in various fields, such as economics, quality control, and research. Discusses the importance of understanding dispersion in decision-making.
|
Students participate in the discussion and suggest other fields where measures of dispersion could be applied.
|
NOTE ON BOARD:
- Mean Deviation: Helps to understand how spread out the data is from the mean.
- Standard Deviation: Indicates how much individual data points differ from the mean.
- Coefficient of Variation: Useful for comparing the variability of different data sets, especially when they have different means.
EVALUATION (5 exercises):
- Calculate the mean deviation for the data set: [4, 8, 12, 15, 18].
- Compute the standard deviation for the data set: [3, 6, 9, 12, 15].
- Calculate the coefficient of variation for a data set with a mean of 25 and a standard deviation of 7.
- Compare the dispersion of two data sets using their standard deviations.
- Explain how a high coefficient of variation affects decision-making.
CLASSWORK (5 questions):
- Find the mean deviation for the data set: [2, 5, 7, 8, 10].
- Calculate the standard deviation for the data set: [5, 8, 12, 14].
- Compute the coefficient of variation for a data set with a mean of 15 and a standard deviation of 4.
- What is the impact of a lower standard deviation on the data set?
- How do you interpret a coefficient of variation of 50%?
ASSIGNMENT (5 tasks):
- Calculate the mean deviation for the data set: [9, 10, 15, 20, 25].
- Find the standard deviation for the data set: [12, 15, 18, 22].
- Compute the coefficient of variation for a data set with a mean of 40 and a standard deviation of 12.
- Describe an industry or field where the coefficient of variation is essential for analysis.
- Provide an example where standard deviation might be more useful than mean deviation.