Agriculture Reference
In-Depth Information
Fig. 8.14
Graphical presentation of a positively skewed distribution
Fig. 8.15
Graphical presentation of a negatively skewed distribution
mesokurtic, and the distribution is platykurtic in
nature. It can be shown that
observations (frequency) decreases. On the
other hand, in a platykurtic distribution, a good
number of classes have almost the same higher
observations and thereby, forming a platelike
structure at the top of the frequency distribution.
Thus, to know the nature of the data, the
measures of central tendency and measures of
dispersion along with skewness and kurtosis of
the frequency distribution are essential.
With the help of the following example, we
shall demonstrate how these analyses could be
taken up using SAS 9.3.
β 2
1
þ β 1 .
Example 8.22.
The frequency distribution of the
length of the leaflet of the three varieties of tube
rose flower is given in Figs. 8.16 , 8.17 and 8.18 .
It is clear from the corresponding figures that the
three distributions vary widely with respect to the
peakedness of the frequency graph.
A leptokurtic distribution means an aggrega-
tion of more observations (frequency) in a par-
ticular class or a couple of classes. Mesokurtic
distribution follows the general norm that at the
lower classes, there are a fewer number of
frequencies, and as the class value increases,
the number of observations (frequency) also
increases then reaches to the peak, and as the
class value increases further,
Example 8.23. The following table gives the
yield attributing characters along with the yield
for 37 varieties. We are to summarize the data in
terms of the different measures of dispersion,
central tendency, skewness, and kurtosis.
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