Finding the median mean and mode is one of the first things you learn when studying statistics. The centre point of a data set can be described by these three metrics, which are referred to as measures of central tendency: mean, median, and mode.
Solving mean median mode problems in exams, real-world data analysis, and even business reporting requires an understanding of the mean median mode formula.This guide contains detailed definitions, formulas, and many mean median mode questions with solutions to help you practice and learn effectively.
Table of Contents
In statistics, the three most frequently used measures of central tendency are mean, median, and mode. They help in understanding the meaning of a set of numbers' typical or central value. Here’s what each one means:
Definition:
The mean is the sum of all values divided by the number of values.
Formula:
Sum of observations
Mean= ————————————
Number of observations
Example:
Data: 4, 6, 8, 10
Mean = (4 + 6 + 8 + 10) ÷ 4 = 28 ÷ 4 = 7
Definition:
The median is the middle value when the numbers are arranged in ascending or descending order.
If the number of values is odd → middle value
If even → average of the two middle values
Example (Odd Number of Values):
Data: 3, 1, 5 → Ordered: 1, 3, 5 → Median = 3
Example (Even Number of Values):
Data: 2, 4, 6, 8 → Ordered: 2, 4, 6, 8 → Median = (4 + 6)/2 = 5
Definition:
The mode is the number that appears most frequently in the data set.
One mode → Unimodal
Two modes → Bimodal
More than two → Multimodal
No repetition → No mode
Example:
Data: 3, 4, 4, 5, 6, 4 → Mode = 4
Learning how to find the median mean and mode will help you interpret and summarize data effectively.
Measure | Data Type | Formula | Variables / Description |
---|---|---|---|
Mean | Ungrouped Data | Mean = (Σx) / n | Σx = Sum of observations, n = Number of observations |
Mean | Grouped Data (Direct Method) | Mean = (Σfᵢxᵢ) / Σfᵢ | fᵢ = Frequency, xᵢ = Midpoint (class mark) |
Mean | Grouped Data (Assumed Mean Method) | Mean = a + (Σfᵢdᵢ / Σfᵢ) | a = Assumed mean, dᵢ = xᵢ – a |
Mean | Grouped Data (Step-Deviation Method) | Mean = a + (Σfᵢuᵢ / Σfᵢ) × h | uᵢ = (xᵢ – a)/h, h = class width |
Median | Ungrouped Data (Odd n) | Median = (n + 1)/2ᵗʰ observation | n = Number of observations |
Median | Ungrouped Data (Even n) | Median = [(n/2)ᵗʰ observation + (n/2 + 1)ᵗʰ observation] / 2 | |
Median | Grouped Data | Median = l + [(N/2 – cf)/f] × h | l = Lower boundary of median class, N = Total frequency, cf = Cumulative frequency before median class, f = Frequency of median class, h = Class width |
Mode | Ungrouped Data | Mode = Most frequent value | |
Mode | Grouped Data | Mode = l + [(f₁ – f₀) / (2f₁ – f₀ – f₂)] × h | l = Lower limit of modal class, f₁ = Frequency of modal class, f₀ = Frequency of class before, f₂ = Frequency of class after, h = Class width |
Empirical Relation | — | Mode = 3 × Median – 2 × Mean | Used for moderately skewed distributions |
Alternative Empirical Relation | — | Mean – Mode = 3 (Mean – Median) | Rearranged version of above |
These mean median mode formula rules apply to most basic statistical questions.
Data = [12, 15, 10, 18, 20]
Ordered = [10, 12, 15, 18, 20]
Mean = (10+12+15+18+20)/5 = 15
Median = 3rd value = 15
Mode = No mode
Data = [8, 10, 14, 18]
Mean = (8+10+14+18)/4 = 12.5
Median = (10 + 14)/2 = 12
Mode = No mode
These help in understanding how to find the median mean and mode practically.
Data: 4, 8, 6, 5, 3
Step 1: Arrange the data in order
3, 4, 5, 6, 8
Mean = (3 + 4 + 5 + 6 + 8) ÷ 5 = 26 ÷ 5 = 5.2
Median = Middle value = 5
Mode = No repeated value → No mode
Data: 14, 16, 20, 18, 16, 22, 24
Step 1: Arrange in ascending order
14, 16, 16, 18, 20, 22, 24
Mean = (14 + 16 + 20 + 18 + 16 + 22 + 24) ÷ 7 = 130 ÷ 7 = 18.57
Median = 4th value = 18
Mode = 16 (appears twice)
Data: 30, 40, 50, 60, 70, 80, 90, 100
Step 1: Arrange in order (already done)
30, 40, 50, 60, 70, 80, 90, 100
Mean = (30 + 40 + 50 + 60 + 70 + 80 + 90 + 100) ÷ 8 = 520 ÷ 8 = 65
Median = (4th + 5th) ÷ 2 = (60 + 70) ÷ 2 = 65
Mode = No repeated value → No mode
Data: 11, 12, 13, 12, 14, 15, 12, 16
Step 1: Arrange in ascending order
11, 12, 12, 12, 13, 14, 15, 16
Mean = (11 + 12 + 13 + 12 + 14 + 15 + 12 + 16) ÷ 8 = 105 ÷ 8 = 13.13
Median = (4th + 5th) ÷ 2 = (12 + 13) ÷ 2 = 12.5
Mode = 12 (appears 3 times)
Data: 3, 5, 5, 5, 7, 9, 11, 13
Step 1: Arrange in ascending order (already done)
3, 5, 5, 5, 7, 9, 11, 13
Mean = (3 + 5 + 5 + 5 + 7 + 9 + 11 + 13) ÷ 8 = 68 ÷ 8 = 8.5
Median = (4th + 5th) ÷ 2 = (5 + 7) ÷ 2 = 6
Mode = 5 (appears 3 times)
Let’s look at some commonly asked mean median mode questions with solutions.
Find the mean, median, and mode of the data set:
Data: 5, 8, 7, 5, 9, 10, 5
Step-by-step solution:
Mean:
Sum = 5 + 8 + 7 + 5 + 9 + 10 + 5 = 49
Number of values = 7
Mean = 49 ÷ 7 = 7
Median:
Arrange in order → 5, 5, 5, 7, 8, 9, 10
Middle value = 4th = 7
Mode:
Most frequent = 5 (appears 3 times)
Mode = 5
Final Answer:
Mean = 7, Median = 7, Mode = 5
Find the mean, median, and mode of:
Data: 12, 15, 20, 18, 15, 25, 30
Mean:
Sum = 12 + 15 + 20 + 18 + 15 + 25 + 30 = 135
Mean = 135 ÷ 7 = 19.29
Median:
Ordered data: 12, 15, 15, 18, 20, 25, 30
Middle value = 4th = 18
Mode:
Most frequent = 15 (appears twice)
Mode = 15
Final Answer:
Mean ≈ 19.29, Median = 18, Mode = 15
Find the mean using the direct method.
Marks (xi) | Frequency (fi) |
---|---|
10 | 5 |
20 | 8 |
30 | 15 |
40 | 12 |
50 | 10 |
Formula:
Mean = ∑(fi × xi) / ∑fi
Step-by-step Table:
xi | fi | fi × xi |
---|---|---|
10 | 5 | 50 |
20 | 8 | 160 |
30 | 15 | 450 |
40 | 12 | 480 |
50 | 10 | 500 |
∑fi = 5 + 8 + 15 + 12 + 10 = 50
∑fi × xi = 1640
Mean = 1640 / 50 = 32.8
Find the mean using the assumed mean method. Take a = 40.
xi | fi |
---|---|
20 | 3 |
30 | 7 |
40 | 9 |
50 | 5 |
60 | 2 |
Step-by-step Table:
xi | fi | di = xi - 40 | fi × di |
---|---|---|---|
20 | 3 | -20 | -60 |
30 | 7 | -10 | -70 |
40 | 9 | 0 | 0 |
50 | 5 | 10 | 50 |
60 | 2 | 20 | 40 |
∑fi = 26
∑fidi = -40
Mean = 40 + (-40 / 26) = 40 - 1.54 = 38.46
Class Interval | Frequency |
---|---|
10 – 20 | 3 |
20 – 30 | 7 |
30 – 40 | 12 |
40 – 50 | 17 |
50 – 60 | 10 |
60 – 70 | 1 |
n = 3 + 7 + 12 + 17 + 10 + 1 = 50, n/2 = 25
Cumulative frequency just above 25 = 39 → median class = 40 – 50
l = 40, F = 22, f = 17, h = 10
Median = 40 + [(25 – 22) / 17] × 10 = 40 + (3 / 17) × 10 = 40 + 1.76 = 41.76
Find the mode from the data:
Class Interval | Frequency |
---|---|
0 – 10 | 4 |
10 – 20 | 6 |
20 – 30 | 10 |
30 – 40 | 15 |
40 – 50 | 8 |
50 – 60 | 5 |
Highest frequency = 15 → modal class = 30 – 40
l = 30, f1 = 15, f0 = 10, f2 = 8, h = 10
Mode = 30 + [(15 – 10) / (2×15 – 10 – 8)] × 10
Mode = 30 + [5 / (30 – 18)] × 10
Mode = 30 + (5 / 12) × 10 = 30 + 4.17 = 34.17
These are typical mean median mode questions with solutions from school and competitive exams.
A teacher recorded scores: 56, 67, 56, 78, and 90.
Find the mean, median, and mode.
Mean = (56+67+56+78+90)/5 = 347/5 = 69.4
Ordered = [56, 56, 67, 78, 90]
Median = 67
Mode = 56
The number of children in 7 families: [2, 3, 4, 3, 2, 5, 3]
Mean = 22/7 = 3.14
Ordered = [2, 2, 3, 3, 3, 4, 5]
Median = 4th value = 3
Mode = 3
These mean median mode problems demonstrate real-life usage.
The table below shows the number of books read by 30 students in a month:
Books Read | Number of Students |
---|---|
0–5 | 4 |
6–10 | 6 |
11–15 | 10 |
16–20 | 6 |
21–25 | 4 |
Find the mean number of books read using the direct method.
Solution:
Classmarks (xi): 2.5, 8, 13, 18, 23
fi: 4, 6, 10, 6, 4
fi × xi: 10, 48, 130, 108, 92
∑fi = 30, ∑fi × xi = 388
Mean = 388 ÷ 30 = 12.93
The following table shows the ages of people in a village:
Age Group | Frequency |
---|---|
0–10 | 2 |
10–20 | 4 |
20–30 | 8 |
30–40 | 12 |
40–50 | 9 |
50–60 | 5 |
Find the median age.
Solution:
Total frequency = 40
n/2 = 20 → Median class = 30–40
l = 30, f = 12, F = 14, h = 10
Median = 30 + [(20 – 14) / 12] × 10 = 30 + 5 = 35
A survey was conducted to know how many hours students study per day:
Hours Studied | Number of Students |
---|---|
0–2 | 5 |
2–4 | 9 |
4–6 | 15 |
6–8 | 10 |
8–10 | 6 |
Find the mode of study hours.
Solution:
Modal class = 4–6
l = 4, f1 = 15, f0 = 9, f2 = 10, h = 2
Mode = 4 + [(15 – 9) / (2×15 – 9 – 10)] × 2
= 4 + (6 / 11) × 2 = 4 + 1.09 = 5.09 hours
1. The weights of 6 children in kg are:
34, 38, 32, 40, 36, 35
Find the average (mean) weight.
2. A student scores 72, 78, 84, 66, and 90 marks in five subjects.
What is the average (mean) score?
3. A shoe store sold the following sizes most in a day:
7, 8, 9, 7, 10, 7, 9, 8, 7
Find the most popular shoe size (mode).
4. The following table shows the number of hours students studied in a week.
Find the mean using the assumed mean method (a = 25).
Hours (xi) |
No. of Students (fi) |
10 – 20 |
5 |
20 – 30 |
8 |
30 – 40 |
10 |
40 – 50 |
7 |
5. The distribution below shows the scores of students in a test.
Find the median score.
Marks |
No. of Students |
0 – 10 |
2 |
10 – 20 |
5 |
20 – 30 |
8 |
30 – 40 |
10 |
40 – 50 |
6 |
6. A survey of 50 houses shows the number of family members as follows.
Find the mode of family size.
No. of Members |
No. of Houses |
1 – 3 |
6 |
4 – 6 |
12 |
7 – 9 |
18 |
10 – 12 |
9 |
13 – 15 |
5 |
7. The ages of a group of 5 students are around a central value. Their ages are approximately equally spaced at 18, 20, 22, 24, and 26.
Find the mean using step-deviation method. Take assumed mean = 22, class size = 2.
Always order the data set before calculating the median or identifying mode.
Use the mean median mode formula carefully.
For large data sets, double-check values and totals.
Be aware of bimodal or multimodal data.
Solve multiple mean median mode questions with solutions for practice.
Practicing various mean median mode problems sharpens your statistical thinking.
In statistics, the mean, median, and mode are fundamental tools for interpreting data. The mode is the number that appears most frequently, the mean is the average, and the median is the middle value. Finding the median, mean, and mode makes it easier to solve problems in the real world and on tests. You can improve your skills and confidently solve data problems by practicing various mean median mode questions with answers and applying the proper mean median mode formula.
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Mean, Median, and Mode - Understand the measures of central tendency with definitions, formulas, and solved examples.
Mean is the average of all numbers.
Median is the middle value when numbers are arranged in order.
Mode is the number that appears most often.
Ordered Data: 12, 12, 13, 13, 14, 14, 14, 16, 19
Mean = (13 + 16 + 12 + 14 + 19 + 12 + 14 + 13 + 14) ÷ 9 = 127 ÷ 9 = 14.11
Median = 5th number = 14
Mode = 14 (appears 3 times)
Mean = (Sum of all values) ÷ (Number of values)
Median = Middle value (or average of two middle values if even number of terms)
Mode = Most frequent value in the data set
Arrange the numbers in order.
If count is odd → pick the middle number.
If count is even → take the average of the two middle numbers.
For simple data: Mode = value that occurs most frequently
For grouped data:
Mode = L + (f₁ − f₀) / (2f₁ − f₀ − f₂) × h
Where:
L = lower limit of modal class
f₁ = frequency of modal class
f₀ = frequency of class before
f₂ = frequency of class after
h = class width
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