A skewed distribution is one which is not symmetrical about the mean, or average. An exponential distribution is one example of a skewed probability distribution.
Continue ReadingSkewed distributions can be detected either by looking at a histogram of the data or by comparing the mean and median. The mean is calculated from the data values, while the median is found by locating the data point in the middle of the data set. If the mean and median are equal, the distribution is not skewed. If the mean is greater or less than the median, the distribution is skewed to the right or the left, respectively. A greater difference between mean and median corresponds to a more severely skewed distribution.
Learn more about StatisticsUnequal class intervals can be used in frequency distribution if the rate of occurrence is very unevenly distributed, with certain classes showing far lower or far greater frequencies than those on either side. In many data tables and histograms, consistent intervals are used, but they cannot always account for irregularities and outliers like those that strategically use unequal intervals.
Full Answer >The coefficient of variation is used in statistics to measure distribution. It can be found from the ratio of the standard deviation over the mean of a set of numbers to calculate both probability and frequency. When it is used in finance, the mean is considered the expected return.
Full Answer >A Z-test is commonly used in statistics to determine whether a given hypothesis is true in a normal distribution or bell curve. Z-tests are optimal for sample sizes of 30 or greater, while student t-tests are best used for lower sample sizes.
Full Answer >The Rayleigh distribution is the distribution of the magnitude of a two-dimensional random vector whose coordinates are independent and identically distributed with mean zero normal variables. It is named for William Strutt, who is also known as Lord Rayleigh.
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