CG Board (CGBSE / SCERT Chhattisgarh) Class 10 Mathematics Solutions | 2026-27 Edition
📚 Chapter Overview:
- Board: Chhattisgarh Board of Secondary Education (CGBSE) / CG SCERT Raipur
- Subject & Unit: Class 10 Mathematics – Unit 8: Statistics (2026-27 Edition)
- Chapter 16: Data Analysis (आँकड़ों का विश्लेषण)
- Medium: Bilingual Step-by-Step Solutions (English Medium + हिंदी माध्यम)
Arithmetic Mean Average
Arithmetic Mean Average
- Ungrouped Data:
Arithmetic Mean (X) =)/)
X = (∑ xi)/(N)
- Discrete Frequency Distribution:
X = (∑ fi xi)/(∑ fi)
Where fi is the frequency and xi is the value of the observation.
- Grouped Data:
X = (∑ fi xi)/(∑ fi)
Where xi is the *Class Mark / Midpoint of each class interval
xi = + Upper Limit)/(2)
### 2. Median
Median is the middlemost value of a dataset when arranged in ascending or descending order.
- Ungrouped Data:
- When n is ODD:
Median = ((n + 1)/(2))th term
- When n is EVEN:
Median = ((n/2)th term + (n/2 + 1)th term)/(2)
- Grouped Data:
First calculate cumulative frequencies (cf) and determine the Median Class where cf ≥ n/2.
Median = l + ((n/2 – cf)/(f)) × h
- l = Lower limit of median class
- n = Total frequency
- cf = Cumulative frequency of class preceding median class
- f = Frequency of median class
- h = Class size
### 3. Mode
Mode is the observation that occurs with the highest frequency in a dataset.
- 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 preceding modal class
- f2 = Frequency of class succeeding modal class
- h = Size of class interval
### 4. Range, Interpolation, and Extrapolation
- Range: The difference between the maximum and minimum values in a dataset.
Range = Maximum Value – Minimum Value
- Interpolation: Finding or estimating data points within the known range of given observations using graphical representation.
- Extrapolation: Estimating values beyond the known range of data points by extending the observed trend on a graph.
Which measure of central tendency Arithmetic Mean Median…
Which measure of central tendency Arithmetic Mean Median…
(i) To determine the most popular size of shoes sold by a shopkeeper.**
(ii) To find the average performance of a student in terminal examinations.
(iii) To select candidates for 10 vacancies out of 21 candidates based on interview marks.
(iv) To determine the average monthly expenditure of a family.
(v) To determine the most common height of students in a class.
(vi) To calculate the average rainfall in a city over a decade.
(vii) Determining the height of doors in a house based on the height of family members.
Data of rainfall mm in 10 months is…
Data of rainfall mm in 10 months is…
Number of months (N) = 10
Average Rainfall = (Sum of rainfall in all months)/(Total number of months)
Sum = 243.50 + 266.00 + 347.70 + 240.00 + 325.20 + 264.80 + 356.30 + 211.60 + 246.90 + 282.70
Sum = 2784.70 mm
Average Rainfall = (2784.70)/(10) = 278.47 mm
Average rainfall is 278.47 mm.
Find the average of the first 21 natural…
Find the average of the first 21 natural…
First 21 natural numbers: 1, 2, 3, 4, …, 21 (N = 21)
Sum of first n natural numbers = (n(n + 1))/(2)
Sum = (21 × 22)/(2) = 21 × 11 = 231
Average = Sum/N = 231/21 = 11
Average of first 21 natural numbers is 11.
Price of petrol in Rupees per liter in…
Price of petrol in Rupees per liter in…
Petrol prices = 28.5, 29.2, 28.8, 29.5, 30.0 (Total observations N = 5)
Sum = 28.5 + 29.2 + 28.8 + 29.5 + 30.0 = 146.0 Rupees
Mean Price = (146.0)/(5) = Rupees 29.2
Mean price of petrol is Rupees 29.2.
Heights in meters of five plants recorded in…
Heights in meters of five plants recorded in…
- Arithmetic Mean:
Sum = 1.80 + 1.99 + 1.95 + 2.02 + 2.02 = 9.78 meters
Mean = (9.78)/(5) = 1.956 ≈ 1.965 meters
- Median:
Arrange in ascending order: 1.80, 1.95, 1.99, 2.02, 2.02 (n = 5, odd)
Median = ((5 + 1)/(2))th term = 3rd term = 1.99 meters
- Mode:
Observation 2.02 occurs maximum number of times (2 times).
Mode = 2.02 meters
Arithmetic mean = 1.965 meters, Median = 1.99 meters, Mode = 2.02 meters.
Weight in kilograms of eight students is as…
Weight in kilograms of eight students is as…
Weights = 30, 32, 33, 38, 37, 41, 35, 40 (N = 8)
Sum = 30 + 32 + 33 + 38 + 37 + 41 + 35 + 40 = 286 kg
Average Weight = 286/8 = 35.75 kg
Average weight is 35.75 kilogram.
Number of students enrolled in a school over…
Number of students enrolled in a school over…
Enrollment data = 1150, 1250, 1360, 1275, 1310 (N = 5)
Sum = 1150 + 1250 + 1360 + 1275 + 1310 = 6345 students
Average Enrollment = (6345)/(5) = 1269 students
Average enrollment over 5 years is 1269 students.
Find the mean of the following data Number…
Find the mean of the following data Number…
| Class Interval | Number of States (fi) | Class Mark (xi) | fi × xi |
|---|---|---|---|
| 25-35 | 11 | 30 | 330 |
| 35-45 | 7 | 40 | 280 |
| 45-55 | 4 | 50 | 200 |
| 55-65 | 4 | 60 | 240 |
| 65-75 | 2 | 70 | 140 |
| 75-85 | 1 | 80 | 80 |
| *Total | ∑ fi = 35 | – | ∑ fi xi = 1390 |
- Frequency Table Calculation:
- Mean Calculation:
X = (∑ fi xi)/(∑ fi) = (1390)/(35) = 39.71428… ≈ 39.71\%
- 5 Conclusions:
- The mean percentage of female teachers across states is 39.71%.
- Maximum number of states (11 states) have 25-35% female teachers.
- Minimum number of states (1 state) falls in the highest range of 75-85% female teachers.
- In 24 states (out of 35), the percentage of female teachers is less than 45%.
- Only 3 states have more than 65% female teachers.
Mean = 39.71%.
Wickets taken by some bowlers in international cricket…
Wickets taken by some bowlers in international cricket…
- Identification of Modal Class:
Maximum frequency is 16, corresponding to class interval 100-150.
Therefore, Modal Class = 100-150.
- Values:
- l = 100 (Lower limit)
- f1 = 16 (Frequency of modal class)
- f0 = 5 (Preceding frequency)
- f2 = 12 (Succeeding frequency)
- h = 50 (Class width)
- Mode Formula Calculation:
Mode = l + [(f1 – f0)/(2f1 – f0 – f2)] × h
Mode = 100 + [(16 – 5)/(2(16) – 5 – 12)] × 50
Mode = 100 + [(11)/(32 – 17)] × 50 = 100 + [11/15] × 50
Mode = 100 + 550/15 = 100 + 36.666… = 136.66
- 5 Conclusions:
- The modal number of wickets taken by bowlers is 136.66 wickets.
- Maximum number of bowlers (16) have taken wickets between 100 and 150.
- Total number of bowlers in the study is 4 + 5 + 16 + 12 + 3 + 2 = 42.
- Most bowlers (28 out of 42) have taken between 50 and 200 wickets.
- Only 2 bowlers have taken more than 250 wickets.
Mode = 136.66.
Literacy rates in percentage of 35 cities are…
Literacy rates in percentage of 35 cities are…
| Literacy Rate | Number of Cities (fi) | Class Mark (xi) | fi × xi |
|---|---|---|---|
| 55-65 | 10 | 60 | 600 |
| 65-75 | 11 | 70 | 770 |
| 75-85 | 8 | 80 | 640 |
| 85-95 | 3 | 90 | 270 |
| *Total | ∑ fi = 35 | – | ∑ fi xi = 2430 |
- Frequency Table Calculation:
- Mean Calculation:
X = (∑ fi xi)/(∑ fi) = (2430)/(35) = 69.4285… ≈ 69.42\%
- 3 Conclusions:
- The average literacy rate across 35 cities is 69.42%.
- Maximum number of cities (11 cities) fall in the literacy rate bracket of 65-75%.
- 22 cities out of 35 have a literacy rate of 65% or higher.
Mean literacy rate is 69.42%.
The following table shows the ages of the…
The following table shows the ages of the…
| Age | Number of Patients (fi) | Class Mark (xi) | fi × xi |
|---|---|---|---|
| 15-25 | 11 | 20 | 220 |
| 25-35 | 21 | 30 | 630 |
| 35-45 | 23 | 40 | 920 |
| 45-55 | 14 | 50 | 700 |
| 55-65 | 5 | 60 | 300 |
| *Total | ∑ fi = 80 | – | ∑ fi xi = 2830 |
- Frequency Table Calculation:
- Mean Calculation:
X = (∑ fi xi)/(∑ fi) = (2830)/(80) = 35.375 ≈ 35.37 years
- 3 Conclusions:
- The average age of patients admitted to the hospital is 35.37 years.
- Maximum number of patients (23) admitted fall in the age group of 35-45 years.
- Total number of patients admitted during the year is 80.
Mean age is 35.37 years.
The following table shows marks obtained by the…
The following table shows marks obtained by the…
| Marks | Number of Students (fi) | Cumulative Frequency (cf) |
|---|---|---|
| 10-20 | 12 | 13 |
| 20-30 | 24 | 37 |
| 30-40 | 32 | 69 |
| 40-50 | 10 | 79 |
| 50-60 | 5 | 84 |
- Cumulative Frequency Table:
- Determination of Median Class:
Total frequency N = 84 ⇒ N/2 = 84/2 = 42.
Cumulative frequency just greater than 42 is 69, corresponding to class interval 30-40.
Therefore, Median Class = 30-40.
- Values:
- l = 30 (Lower limit)
- cf = 37 (Preceding cumulative frequency)
- f = 32 (Frequency of median class)
- h = 10 (Class size)
- Median Formula Calculation:
Median = l + ((N/2 – cf)/(f)) × h
Median = 30 + ((42 – 37)/(32)) × 10 = 30 + (5/32) × 10
Median = 30 + 50/32 = 30 + 1.5625 ≈ 31.56
- 3 Conclusions:
- The median mark of the students is 31.56.
- Exactly 50% of the students scored less than 31.56 marks, and 50% scored more.
- The maximum concentration of students (32 students) scored between 30 and 40 marks.
Median = 31.56.
💡 Teacher Nudge / :