R-Programming Assignment

Running head: R-PROGRAMMING 1
R – Programming Assignment
By (Name of Student)
(Institutional Affiliation)
(Date of Submission)
Page 1 of 5

R-PROGRAMMING 2
Question 1 (25 marks)
a) Describe the structure of the film.txt data. (2 marks)
The film data is a data set that contains five variables namely;
TopLeft, TopRight, BottomRight, BottomLeft.
The five variables have numerical values of measurements
b) Produce and interpret univariate QQ plots and histograms and univariate
ShapiroWilks tests of normality for each of the four film thickness variables. Which is
the most non-normally distributed variable? (5 marks)
Histogram of TopRight
TopRight
F re q u e n c y
0 200 400 600 800 1000 1200
0 2 4 6 8 1 0
c) Produce and interpret perspective and contour plots for the top-right and top-left film
thickness variables. What is an inherent problem with using these plots to assess
MVN? (3 marks)
d) Do the analysis necessary to provide the results of the Mardia, Henze-Zirkler and
Royston tests of MVN based on all four film thickness variables. Include in your
interpretation: (10 marks)
• The Chi-Square QQ plot and describe how it is constructed and its relationship to
the univariate normal QQ plots as part of your interpretation.
• What is a key limitation of these MVN statistical tests?
e) One way to try and meet the MVN assumption could be to remove some of the
variables from the multivariate analysis (do not perform this analysis). Suggest three
Page 2 of 5