Mathematics and Statistics · Class 11 Commerce
Ch 12Skewness — Class 11 Mathematics and Statistics, concept-first.
Earlier chapters of the Maharashtra State Board Std XI Mathematics and Statistics (Commerce) course measured where a set of data centres (mean, median, mode) and how widely it spreads (range, quartile deviation, standard deviation).
Key concepts
Hover a concept to preview it and jump to its most relevant Q&A.
Karl Pearson's Coefficient of Skewness
Karl Pearson's coefficient of skewness is Sk = (Mean minus Mode) divided by the Standard Deviation, used whenever the distribution has a clear, well-defined mode.
Most relevant Q&A
- The mean of a distribution is $32$, its mode is $35$ and its standard deviation is $6$. Find Karl Pearson's coefficient of skewness and stat…Free
- For a distribution the mean is $29$, the median is $30$ and the standard deviation is $5$. The mode is ill-defined. Find Karl Pearson's coef…Free
- Karl Pearson's coefficient of skewness of a distribution is $0.4$, its mean is $48$ and its standard deviation is $10$. Find the mode.Preview
- For a distribution the mean is $45$, the mode is $39$ and the standard deviation is $6$. Compute Karl Pearson's coefficient of skewness and…Free
- The mean of a distribution is $50$, its median is $48$ and its standard deviation is $10$. The mode cannot be determined reliably. Find Karl…Free
Chapter contents
The NCERT structure, section by section. Open a section to see its questions, then read the concept-first solution.
Meaning of Skewness
Earlier chapters of the Maharashtra State Board Std XI Mathematics and Statistics (Commerce) course measured where a set of data centres (mean, median, mode) and how widely it spreads (range, quartile…
Types of Skewness
Skewness is classified by the side on which the longer tail lies and, equivalently, by the relative positions of the mean, median and mode.
Karl Pearson's Coefficient of Skewness
Knowing the direction of skewness from the order of the averages is not enough; a business analyst needs a single number that gives its degree as well, and that can be compared across distributions.
Bowley's (Quartile) Coefficient of Skewness
Karl Pearson's coefficient needs the standard deviation and the mean, both of which are badly disturbed by a single extreme value and cannot even be computed for an open-ended distribution (one whose…
Interpreting and Comparing Skewness
Both coefficients are relative measures — pure numbers — and are read the same way regardless of the data's units.
Exercises
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- Q9The mean of a distribution is $32$, its mode is $35$ and its standard deviation is $6$. Find Karl Pearson's coefficient of skewness and stat…Free
- Q10For a distribution the mean is $29$, the median is $30$ and the standard deviation is $5$. The mode is ill-defined. Find Karl Pearson's coef…Free
- Q11For a distribution $Q_1 = 20$, $Q_2 = 26$ and $Q_3 = 36$. Find Bowley's coefficient of skewness.Free
- Q12Karl Pearson's coefficient of skewness of a distribution is $0.4$, its mean is $48$ and its standard deviation is $10$. Find the mode.Preview
- Q13In a positively skewed distribution, which of the following relationships between the averages is correct? (a) Mean = Median = Mode (b) Mean…Preview
- Q14For a distribution the median $Q_2 = 40$, the third quartile $Q_3 = 50$ and Bowley's coefficient of skewness is $-0.2$. Find the first quart…Preview
- Q15State what is meant by skewness of a frequency distribution, and distinguish between a symmetric distribution and a positively skewed one in…Preview
More questions
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- Example 1For a distribution the mean is $45$, the mode is $39$ and the standard deviation is $6$. Compute Karl Pearson's coefficient of skewness and…Free
- Example 2The mean of a distribution is $50$, its median is $48$ and its standard deviation is $10$. The mode cannot be determined reliably. Find Karl…Free
- Example 3For a distribution $Q_1 = 24$, $Q_2 = 30$ and $Q_3 = 40$. Compute Bowley's coefficient of skewness and comment on the type of skewness.Free
- Example 4Karl Pearson's coefficient of skewness of a distribution is $0.5$, its mode is $20$ and its standard deviation is $8$. Find the mean.Preview
- Example 5For a distribution the mean is $40$, the median is $42$ and Karl Pearson's coefficient of skewness is $-0.3$. Find the standard deviation an…Preview
- Example 6For a distribution $Q_1 = 15$, the median $Q_2 = 20$ and Bowley's coefficient of skewness is $0.2$. Find the third quartile $Q_3$.Preview
- Example 7Compute Karl Pearson's coefficient of skewness for the following distribution and comment on its shape. | $x$ | 5 | 10 | 15 | 20 | 25 | |---…Preview
- Example 8For a certain distribution the mean, median and mode are all equal to $60$. What is its coefficient of skewness, and what does this tell you…Preview