0
Why do you multiply the interquartile range by 1.5 to find the outlier?
Wiki User
∙ 14y ago
By definition a quarter of the observations are below the lower quartile and a quarter are above the upper quartile. In all, therefore, half the observations lie outside the interquartile range. Many of these will be more than the inter-quartile range (IQR) away from the median (or mean) and they cannot all be outliers. So you take a larger multiple (1.5 times) of the interquartile range as the boudary for outliers.
Wiki User
∙ 14y ago
Add your answer:
Earn +20 pts
Does a box plot represent an interquartile range?
If presents you with the upper and lower quartile range, although you have to do calculations in order to find the interquartile range, so no, it does not,
How do you find the inter quartile?
interquartile range is upper quartile (or quartile 3) minus lower quartial ( or quartial 1 ) For example the quartile 3 is 165 and the quartile 1 is 125. The interquartile range is 40. You can go online and see pages. Thank you
How do you find the semi-interquartile range with only the mean and standard deviation?
In general, you cannot. If the distribution can be assumed to be Gaussian [Normal] then you could use z-scores.
How can you find the interquartile in a stem and leaf plot?
The range is the difference between the maximum score and the minimum score. Let's look at an example. [Figure2] The smallest number in the stem-and-leaf plot is 22. You can see that by looking at the first stem and the first leaf. The greatest number is the last stem and the last leaf on the chart. In this case, the largest number is 55. To find the range, subtract the smallest number from the largest number. This difference will give you the range. 55 - 22 = 33 The range is 33 for this set of data.
How do you find an outlier?
It is the biggest or lowest number out of the set. The number would be way different than the rest. Example: 14 12 52 17 19 The outlier would be 52 because it is the biggest number. Example: 59, 42, 77, 65, 10 The outlier would be 10 because it is the lowest number.
How do you find the interquartile range in a set of data?
how do you find the interquartile range of this data
Does a box plot represent an interquartile range?
If presents you with the upper and lower quartile range, although you have to do calculations in order to find the interquartile range, so no, it does not,
How do you determine how the outlier affects the mean median mode and range?
Calculate the mean, median, and range with the outlier, and then again without the outlier. Then find the difference. Mode will be unaffected by an outlier.
What is the semi interquartile range?
The semi interquartile range is a measure for spread or dispersion. To find it you have to subtract the first quartile from Q3 and divide that by 2, (Q3 - Q1)/2
How do you find the interquartile range of a data?
The Inter-quartile range is the range of the middle half of the data. It is the difference between the upper and lower quartile.Example: 35,80,100 110,120,120,170,180.The Inter-quartile range would be 145-90 or 55To find the interquartile range, you:1) Arrange the data in numerical order.2) Then find the median of the data sets.3) Find the median of the top half and bottom half. (of the set of numbers)4) The groups you now have are "quartiles"5) Find the interquartile range. (subtract the smaller range from the range)
What is best Interquartile range or Median absolute deviation?
The answer depends on the purpose. The interquartile range and the median absolute deviation are both measures of spread. The IQR is quick and easy to find whereas the MAD is not.
How do you find the semi interquartile range of a set of statistics?
You find the semi interquartile range by subtracting the 25th percentile (Q1) from the 75th (Q3) percentile and dividing by 2. So, the formula looks like : (Q3 - Q1)/2
How is the interquartile range calculated?
Find the difference between the values for quartile 3 and quartile 1.
How is interquartile range calculated?
Find the difference between the values for quartile 3 and quartile 1.
How do you find the inter quartile?
interquartile range is upper quartile (or quartile 3) minus lower quartial ( or quartial 1 ) For example the quartile 3 is 165 and the quartile 1 is 125. The interquartile range is 40. You can go online and see pages. Thank you
How do you detect outliers?
There is no single definition of an outlier, but they are observations that are way out of line in comparison to other observations - either too small or too large. One way is to first find the inter-quartile range (IQR). Now multiply this by 1.5 and add it to the upper quartile and subtract it from the lower one. Any point beyond these values is an outlier.
How do you find the limit of outliers in box and whisker plot?
To find the limits of outliers in box and whisker plots, you first must determine the Interquartile Range. The Interquartile Range is the difference between the Upper Quartile and the Lower Quartile. For instance, if my Upper Quartile = 87 and my Lower Quartile is 52, then 87 - 52= 35. 35 is the Interquartile Range (IQR).Next, you use the formula 1.5 x IQR to determine if you have any outliers.Example:1.5 x 35 = 52.5Now determine the limit for the Upper Quartile by adding 52.5 to the Upper Quartile.Example:52.5 + 87 = 139.5139.5 is the limit for the Upper Quartile.Next, determine the limit for the Lower Quartile by subtracting the Lower Quartile from 52.5Example52 - 52.5 = -0.5-0.5 is the limit for the Lower QuartileThus, the LIMITS are -0.5 and 139.5. In order for a number to be considered an outlier, it must either be less than -0.5 or greater than 139.5
