Week: Unit IV: Mesures of Deviation or Dispersion | AST1231: Introduction to Statistics (CoL) | University of Rwanda

Section outline

Aims of the unit
This unit aims to help you to understand the different steps followed on the deviation of statistical parameters like quartiles, quartiles deviations, ranges, variance, and standard deviations with their specific characters and determination.

Learning Outcomes:
After successful completion of the unit, you will be expected to be able to:

Explain the concepts regarding this unit,

Demonstrate the mechanism and the technic that help you to manipulate the necessary formulae, and arrive to execute any possible calculations,

To do any application required and get the true solutions without difficulty

Indicative content:

Determination of Range,

Calculation of quartiles and deduce the quartile deviations,

Interpretation and roles of quartiles and quartile deviations,

Variance analysis, its determination, and its statistical role,

Standard deviation determination and its statistical significance

Reference:

Read textbooks,

Published papers, and

Articles, materials on measures of deviation or dispersion through the University of Rwanda Library website: https:/library.ur.ac.rw/ and materials uploaded below.

Unit outline of this unit:
Attached is the course outline of quartile deviation, variance, and standard deviation, it describes the sub-units covered by the unit and practice to be conducted in the unit.
- Select activity SOURCE 1: Lecture Notes on measures of unit 4.1
  
  SOURCE 1: Lecture Notes on measures of unit 4.1 File PDF
  
  Students must
  
  Mark as done
  
  794.0 KB
- Select activity Source 2: Statistics for management and economics(11th edition) by Gerald Keller
  
  Source 2: Statistics for management and economics(11th edition) by Gerald Keller Book
  
  This book contains many chapters, look for chapters related to Unity 4. It can be accessed from https://www.amazon.com/Statistics-Management-Economics-Gerald-Keller/dp/1285425456
- Select activity Quiz 4.1 : Quartiles and Quartile deviations
  
  Quiz 4.1 : Quartiles and Quartile deviations
  
  Students must
  
  View
  
  Receive a grade
  
  Quartiles. Quartile deviations and semi-interquartile ranges will be the mains points that you (student) will be focused in this e-tivity; you must be able to
  understand the steps to follow and arrive to know well the ways to follow until you find that quartile Q1, Q2 and Q3,and determine their position on the graphs
  with their meanings and their interpretations.
  Quartiles Deviations:
  Similarly, as quartiles are now known, you will follow the steps of deducing the mechanism or technics helping you to determine semi-interquartile range then quartile deviation by applying the appropriate formula studied to determine those parameters,(see, Unit 4.1), in the Lecture notes. This quiz aims to guide you to review how to calculate the quartiles and deduce through the appropriate formulae the quartile deviation.
- Select activity Quiz 4.2 : Standard Deviation
  
  Quiz 4.2 : Standard Deviation
  
  At these steps, read more to differentiate the difference between measures of central tendency and measures of dispersion. This reading will enable you to understand well those measures and go deeply for the appropriate comment to each type of measure of deviation. In addition, after reading, through the notes in the above
  source related to unit 4.1, you will be guided and able to understand and discuss well this e-tivity and arrive to do it without difficulty.
  
  Not available unless: The activity Quiz 4.1 : Quartiles and Quartile deviations is marked complete
- Select activity E-tivity 4.3: Variance from its components and derivative
  
  E-tivity 4.3: Variance from its components and derivative Forum
  
  This e-tivity will enable you to understand the role of standard deviation in a given distribution.
  
  You have first to review the measures of central tendency and for the measures of dispersions in details. After understanding them well through the sources provided in the note of unit 4, with different components related to the variance, you will easily make a group discuss among the classmates, first to ensure on the components of variance and their different measures. You have also to get a common comprehension even of the used formulae. Also, find out how the task
  will be done. After the member groups have the common understand, then each student solves alone this e-tivity, which is presented below: After getting the variance
  value, you will deduce its standard deviation or you can proceed by calculation standard deviation and square it. At that steps the obtained value is called ‘’VARIANCE’’.
  
  Task: You will follow the steps of getting the standard deviation from the variance.
  
  Given five values of a population: 8, 3, 7,3, and 4.
  a. Determine the mean of the population
  b. Find the variance of population and the population standard deviation.
  
  c. Post your answers in the forum and comment on the answers from your peers.
  
  Not available unless: The activity Quiz 4.2 : Standard Deviation is marked complete
- Select activity Source 3: Measures of Dispersion
  
  Source 3: Measures of Dispersion URL
  
  Students must
  
  Mark as done
  
  After watching this video focusing on measures of dispersion p 20-25, and help to understand the particular important points.