Summary
Summary Dispersion and skewness
- Module
- Statistics
- Institution
- London School Of Business And Finance
summary of this topic Dispersion and skewness
[Show more]
Seller
Follow
Content preview
Definition• Measures of dispersion are descriptive
statistics that describe how similar a set of
scores are to each other
– The more similar the scores are to each other, the
lower the measure of dispersion will be
– The less similar the scores are to each other, the
higher the measure of dispersion will be
– In general, the more spread out a distribution is,
the larger the measure of dispersion will be
1
, Why Study Dispersion?
– A measure of location, such as the mean or the median,
only describes the center of the data. It is valuable from
that standpoint, but it does not tell us anything about the
spread of the data.
– For example, if your nature guide told you that the river
ahead averaged 3 feet in depth, would you want to wade
across on foot without additional information? Probably
not. You would want to know something about the variation
in the depth.
– A second reason for studying the dispersion in a set of data
is to compare the spread in two or more distributions.
2
, Measures of Dispersion
• Which of the 125
distributions of scores 100
75
has the larger 50
25
dispersion? 0
1 2 3 4 5 6 7 8 9 10
The upper distribution
has more dispersion 125
100
because the scores are 75
50
more spread out 25
0
1 2 3 4 5 6 7 8 9 10
That is, they are less
similar to each other
3
, Measures of Dispersion
1. Absolute measures of dispersion
The range
The semi-interquartile range (SIR)
Mean deviation
Variance / standard deviation
2. Relative measures of dispersion
Coefficient of range,
Coefficient of I.Q
Coefficient of variation
4
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller muhsin212. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £8.36. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83750 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 14 years now