Statistics Class 10 Maths — Revision Notes
This chapter covers methods to collect, organize, and analyze data using statistical measures. Students learn mean, median, mode, and graphical representat
TL;DR: This chapter covers methods to collect, organize, and analyze data using statistical measures. Students learn mean, median, mode, and graphical repres…
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
This chapter covers methods to collect, organize, and analyze data using statistical measures. Students learn mean, median, mode, and graphical representat
Measures of Central Tendency
- Mean: sum of all values divided by number of values
- Median: middle value when data arranged in order
- Mode: value occurring most frequently
- For grouped data: use class marks and frequencies
Mean of Grouped Data
- Mean = sum(f x x) / sum(f) where f is frequency, x is class mark
- Class mark = (lower limit + upper limit) / 2
- Assumed mean method: choose assumed mean, find deviations, calculate mean
- Step deviation method: use h/d where h is class width
Median and Mode of Grouped Data
- Median = l + (n/2 - cf) / f x h where l is lower class, cf is cumulative frequency, f is frequency, h is class width
- Modal class: class with highest frequency
- Mode = l + (f1 - f0) / (2f1 - f0 - f2) x h where f1 is modal frequency
Data Representation
- Histogram: bars for grouped data with frequencies as heights
- Frequency polygon: line connecting class marks at frequencies
- Pie chart: circle divided into sectors representing frequencies
- Cumulative frequency curve (ogive): smooth curve through cumulative frequencies
Key Terms
- Mean: Average of all values in dataset
- Median: Middle value in ordered dataset
- Mode: Value appearing most frequently in dataset
Frequently Asked Questions
How do you find median of grouped data?
Find n/2 where n is total frequency. Locate class where cumulative frequency first exceeds n/2. Apply formula: median = l + (n/2 - cf)/f x h.
When is mean not a good measure of central tendency?
When data has outliers (very large or very small values), mean gets skewed. In such cases, median is better measure of central tendency.
More Class 10 Maths Revision Notes
- Real Numbers
- Polynomials
- Pair of Linear Equations in Two Variables
- Quadratic Equations
- Arithmetic Progressions
- Triangles
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