In terms of SQL, Skewness is an asymmetry in the distribution of the data values or how the value is distributed accross.
Consider a table employees where you have millions of employee records and a column in that table which have either a value as 0 or 1 (F or T). Now consider out of one million records, the 1 value is applicable for only 2000 employees and the rest are having value as 0. This asymmetry or inproportionate data tells us that the column contains highly skewed data.
There isn't a specific chart for skewed data, but you could use a number of different charts to show that data is skewed. An Area chart could be used for example, or a column chart could also work. It would depend in the nature of the data.
mode
There is no meaningful average wen data are categorical (qualitative). Also, the arithmetic mean is not a good measure of central tendency when the data distribution is skewed.
the data value that is much higher or lower than the other data given is called an outlier
If the skewness is different, then the data sets are different.Incidentally, there is one [largely obsolete] definition of skewness which is in terms of the mean and median. Under that definition, it would be impossible for two data sets to have equal means and equal medians but opposite skewness.
When the data are skewed to the right the measure of skewness will be positive.
The population data may be skewed and thus the mean is not a valid statistic. If mean > median, the data will be skewed to the right. If median > mean, the data is skewed to the left.
There isn't a specific chart for skewed data, but you could use a number of different charts to show that data is skewed. An Area chart could be used for example, or a column chart could also work. It would depend in the nature of the data.
i) Since Mean<Median the distribution is negatively skewed ii) Since Mean>Median the distribution is positively skewed iii) Median>Mode the distribution is positively skewed iv) Median<Mode the distribution is negatively skewed
skewed
A positively skewed or right skewed distribution means that the mean of the data falls to the right of the median. Picturewise, most of the frequency would occur to the left of the graph.
Measurement Scale Best measure of the 'middle' Numerical mode Ordinal Median Interval Symmetrical data- mean skewed data median Ratio Symmetrical data- Mean skewed data median
If it is very highly skewed then the mode is best.
When the data distribution is negatively skewed.
See related links.
If the median is exactly in the middle of the box, and the box is exactly in the middle of the whiskers, then skewness = 0. The data are skewed if either the median is off-centre in the box, or if the box is off-centre overall.
This is known as a skewed data set.