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Home > Statistical Methods calculators > Sample Skewness, Kurtosis for ungrouped data example
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Sample Skewness Example for ungrouped data
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- Formula & Example
- Sample Skewness Example
- Sample Kurtosis Example
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Other related methods
- Mean, Median and Mode
- Quartile, Decile, Percentile, Octile, Quintile
- Population Variance, Standard deviation and coefficient of variation
- Sample Variance, Standard deviation and coefficient of variation
- Population Skewness, Kurtosis
- Sample Skewness, Kurtosis
- Geometric mean, Harmonic mean
- Mean deviation, Quartile deviation, Decile deviation, Percentile deviation
- Five number summary
- Box and Whisker Plots
- Construct an ungrouped frequency distribution table
- Construct a grouped frequency distribution table
- Maximum, Minimum
- Sum, Length
- Range, Mid Range
- Stem and leaf plot
- Ascending order, Descending order
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2. Sample Skewness Example
1. Calculate Sample Skewness from the following data
`85,96,76,108,85,80,100,85,70,95`
Solution:
Skewness :
Mean `bar x=(sum x)/n`
`=(85+96+76+108+85+80+100+85+70+95)/10`
`=880/10`
`=88`
| `x` | `(x - bar x)`
`= (x - 88)` | `(x - bar x)^2`
`= (x - 88)^2` | `(x - bar x)^3`
`= (x - 88)^3` | | 85 | -3 | 9 | -27 | | 96 | 8 | 64 | 512 | | 76 | -12 | 144 | -1728 | | 108 | 20 | 400 | 8000 | | 85 | -3 | 9 | -27 | | 80 | -8 | 64 | -512 | | 100 | 12 | 144 | 1728 | | 85 | -3 | 9 | -27 | | 70 | -18 | 324 | -5832 | | 95 | 7 | 49 | 343 | | --- | --- | --- | --- | | 880 | 0 | 1216 | 2430 |
Sample Standard deviation `S = sqrt((sum (x - bar x)^2)/(n-1))`
`=sqrt(1216/9)`
`=sqrt(135.1111)`
`=11.6237`
Sample Skewness `= (sum(x - bar x)^3)/((n-1)*S^3)`
`=2430/(9*(11.6237)^3)`
`=2430/(9*1570.4951)`
`=0.1719`
2. Calculate Sample Skewness from the following data
`10,50,30,20,10,20,70,30`
Solution:
Skewness :
Mean `bar x=(sum x)/n`
`=(10+50+30+20+10+20+70+30)/8`
`=240/8`
`=30`
| `x` | `(x - bar x)`
`= (x - 30)` | `(x - bar x)^2`
`= (x - 30)^2` | `(x - bar x)^3`
`= (x - 30)^3` | | 10 | -20 | 400 | -8000 | | 50 | 20 | 400 | 8000 | | 30 | 0 | 0 | 0 | | 20 | -10 | 100 | -1000 | | 10 | -20 | 400 | -8000 | | 20 | -10 | 100 | -1000 | | 70 | 40 | 1600 | 64000 | | 30 | 0 | 0 | 0 | | --- | --- | --- | --- | | 240 | 0 | 3000 | 54000 |
Sample Standard deviation `S = sqrt((sum (x - bar x)^2)/(n-1))`
`=sqrt(3000/7)`
`=sqrt(428.5714)`
`=20.702`
Sample Skewness `= (sum(x - bar x)^3)/((n-1)*S^3)`
`=54000/(7*(20.702)^3)`
`=54000/(7*8872.2715)`
`=0.8695`
3. Calculate Sample Skewness from the following data
`73,70,71,73,68,67,69,72,76,71`
Solution:
Skewness :
Mean `bar x=(sum x)/n`
`=(73+70+71+73+68+67+69+72+76+71)/10`
`=710/10`
`=71`
| `x` | `(x - bar x)`
`= (x - 71)` | `(x - bar x)^2`
`= (x - 71)^2` | `(x - bar x)^3`
`= (x - 71)^3` | | 73 | 2 | 4 | 8 | | 70 | -1 | 1 | -1 | | 71 | 0 | 0 | 0 | | 73 | 2 | 4 | 8 | | 68 | -3 | 9 | -27 | | 67 | -4 | 16 | -64 | | 69 | -2 | 4 | -8 | | 72 | 1 | 1 | 1 | | 76 | 5 | 25 | 125 | | 71 | 0 | 0 | 0 | | --- | --- | --- | --- | | 710 | 0 | 64 | 42 |
Sample Standard deviation `S = sqrt((sum (x - bar x)^2)/(n-1))`
`=sqrt(64/9)`
`=sqrt(7.1111)`
`=2.6667`
Sample Skewness `= (sum(x - bar x)^3)/((n-1)*S^3)`
`=42/(9*(2.6667)^3)`
`=42/(9*18.963)`
`=0.2461`
This material is intended as a summary. Use your textbook for detail explanation.
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