0
procedure:
step 1: arrange your raw data in increasing order.
step 2: find the Q1 is the size of the (n+1)/4th value.
step 3: find the Q3 is the size of the 3(n+1)/4th value.
Quartile Deviation(QD)= (Q3-Q1)/2
for example: 87 ,64,74,13,19,27,60,51,53,29,47 is the given data
step 1: 13,19,27,29,47,51,53,60,64,74,87
step 2: (n+1)/4=3 therefore Q1=27
step 3: 3(n+1)/4=9 therefore Q3=6
implies QD=18.5
Quartile
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Explain the purpose of calculating standard deviation and quartile deviation?
Standard deviation helps planners and administrators to arrive at a figure that could be used to determine a range that can effectively describe a given set of numerical information/data; and based on which a decision concerning a system of those data can be made.
Uses of quartile deviation?
This helps to show where things may not follow the norm. Quartiles help you to keep data organized and so a deviation would show how it would vary.
Can interquartile range be used for any data eg data below the lower quartile to find if the data is spread out or close together or must we use the lower quartile for data below the lower quartile?
No, interquartile range cannot be for any data. The lower quartile for data must be used below the lower quartile.
How do you find the Quartile of a number?
A number does not have a quartile, a set of data does. The lower quartile of a set of data set is a value, in the data set, such that a quarter of the date set are smaller and three quarters are larger. The upper quartile is defined similarly. The middle quartile, better known as the median, divides the data set in two.
What statistical measure tells you how to spread out the data are?
There are many:Range.Inter [ ] Range : where the middle part may be quartile, quintile, decile or percentile. Other options are possible but less common.Mean absolute deviation.Mean squared deviation (variance).Standard error.Standard deviation.
Calculating quartile deviation for grouped and ungrouped data?
(q3-q1)/2
What is the purpose of quartile deviation?
In a data sample, the purpose of quartile deviation is a way to measure data dispersion instead of using the range. The quartile deviation is found by subtracting the lower quartile from the upper quartile, and dividing this result by two.
How do you get the Quartile Deviation in a grouped data?
Test
Explain the purpose of calculating standard deviation and quartile deviation?
Standard deviation helps planners and administrators to arrive at a figure that could be used to determine a range that can effectively describe a given set of numerical information/data; and based on which a decision concerning a system of those data can be made.
What is the relation between quartile deviation and standard deviation?
Strictly speaking, none. A quartile deviation is a quick and easy method to get a measure of the spread which takes account of only some of the data. The standard deviation is a detailed measure which uses all the data. Also, because the standard deviation uses all the observations it can be unduly influenced by any outliers in the data. On the other hand, because the quartile deviation ignores the smallest 25% and the largest 25% of of the observations, there are no outliers.
When to use quartile deviation?
When you are looking for a simple measure of the spread of the data, but one which is protected from the effects of extreme values (outliers).
Uses of quartile deviation?
This helps to show where things may not follow the norm. Quartiles help you to keep data organized and so a deviation would show how it would vary.
What is the first step in calculating the standard deviation?
Collecting the data might be a good start.
What is the quartile deviation for this data X 2 3 4 5 6 and f 3 4 8 4 1?
1
Can interquartile range be used for any data eg data below the lower quartile to find if the data is spread out or close together or must we use the lower quartile for data below the lower quartile?
No, interquartile range cannot be for any data. The lower quartile for data must be used below the lower quartile.
Which value is NOT always a number in the data set it represents?
The range, median, mean, variance, standard deviation, absolute deviation, skewness, kurtosis, percentiles, quartiles, inter-quartile range - take your pick. It would have been simpler to ask which value IS in the data set!
How do you find the Quartile of a number?
A number does not have a quartile, a set of data does. The lower quartile of a set of data set is a value, in the data set, such that a quarter of the date set are smaller and three quarters are larger. The upper quartile is defined similarly. The middle quartile, better known as the median, divides the data set in two.
