MATH1041 Statistics for Life and Social Science

Data: Together with this document, you should have received your unique dataset in an e-mail sent to your official university email address. The data (that is, your dataset) are available in a text file with the name 5380675.csv. If you have not received your dataset (double check your UNSW email inbox and the spam folder), please contact your lecturer.

Submission due date: Tuesday 9th April (Week 9) before 11:59 PM (Sydney time, AEST). Note that a late penalty of 5% of the maximal possible mark per day will apply. No assignment will be accepted more than five days after the deadline.

(*) See the next pages and the “Assessments Hub” on Moodle for details, help and explanations about the assignment and typesetting.

Note that your assignment and dataset is unique. You cannot show your dataset or your assignment to anyone. It is your responsibility to keep your dataset and your assignment secret. Also, your assignment must be your own work. You cannot get any outside help in any form. If you have a question about the assignment, the only places where you can ask it is on the MATH1041 Assignment forum, provided you do not reveal your data, or at a staff consultation.

• Regarding the overall assignment structure, please answer all questions in the given order (that is, 1.a., 1.b., ... etc). Do not re-write the assignment questions again, only their label (write “3.e.” for instance when you start question 3.e.). Keep your answers brief, clear and concise. There is NO need to reproduce the cover sheet, i.e., the first 5 pages of the pdf file sent to you, in your assignment.

• Start your answer to each Question (1, 2, etc.) on a new page. Each Question should start on a new page, but sub-parts of a Question (such as Question 3.d., 3.e.) should continue on the same page.

• You are required to type up your entire assignment (in Microsoft Word, Google docs, LATEX, Overleaf or RMarkdown) including any equations. The only exception are the plots produced by RStudio, for which you can save the figures (use “export” in the bottom right window in RStudio) which you then paste in your assignment. Nothing can be handwritten then scanned. As a UNSW student, you can download Microsoft Word for free, see: https://www.myit.unsw.edu.au/software-students.

• As in any properly typeset document containing mathematic symbols, you must use an equation editor for all maths symbols. For instance, you should write “X is normal”, rather than “X is normal” (Notice how the ‘X’ looks different?) and you should write “tobs = 1.23”, rather than “tobs = 1.23”. The marking scheme for this criterion is the following: Are mathematical symbols typeset using the equation editor? 2 marks for ‘almost always’, 1 mark for ‘sometimes’, 0 mark for ‘rarely’. Help about Microsoft equation editor can be found in a document called Microsoft Word Equation editor help for MATH1041 located on Moodle in the Assignment (20%) section within the Assessments Hub section of the MATH1041 Moodle page.

• You should add some working out for the questions involving calculations; do not just give the final answer. Note that you may get partial marks for clear explanations and a correct method even if you get the wrong answer. However, try to keep your solutions brief and concise. Depending on what the question is asking, your working out could consist of RStudio commands, a formula, or perhaps the main steps explaining how you arrived at your answer. You do not need to add all your R-code.

• Keeping your results to 3 or 4 significant figures should be fine. If there are multiple steps in a calculation, do not round any numbers until you have reached the final step. To help you do calculations correctly in RStudio without rounding, values should be stored as variables, rather than copying the output number into a further calculation. For example, if you are constructing a confidence interval and need to calculate t ∗ , you should write the code: tstar <- qt(0.975, df = 10) and then use the variable tstar in calculating your confidence interval, rather than pasting in the number 2.228139.

• There is no requirement for font size and line spacing but please make sure your assignment is readable — do not make the font size too small or the spacing too compact.

• If the question asks you to produce a graph/plot, you should always include that graph in your answer, unless otherwise specified.

Scenario Do NOT copy-paste these data 

Parkinson’s disease (PD), or simply Parkinson’s, is a chronic degenerative disorder of the central nervous system in the brain that affects both the motor system and non-motor systems. The symptoms usually emerge slowly, and as the disease progresses, non-motor symptoms become more common. Early symptoms are tremor, rigidity, slowness of movement, and difficulty with walking, speaking or swallowing.

the data on the previous page as your dataset.

The first step is to read the data into RStudio. The data format is like what you have already worked with in the Weekly Mobius lessons. Follow the instructions given in section R1.4 “How to import a text file into RStudio” of the RStudio “How-To-Manual” available on Moodle. Alternatively, you can also review your lecture slides to find the R function to use to import a CSV file into RStudio. Two arguments that are often used when calling this function are header = TRUE (to indicate that names of variables are present on the first line in the file) and row.names = 1 (to indicate that names of the cases are provided in the first column). Another very important argument is colClasses which takes a vector of classes to be assumed for the columns (such as "character" for strings, "factor" for a categorical variable, and "numeric" for a quantitative variable). Once you have uploaded the data then you are ready to start your analysis!