The Flinders University of South Australia School of Computer Science, Engineering and Mathematics
STAT2700 Applied Statistics Laboratory
Take-Home Test 2
Due 3pm, Thursday, 2nd April, 2015
Submitting Your Test....
• Your submission must be your own independent work.
• Submission method for this Test is ON-LINE submission via FLO only. Hard copy submission or electronic submission via email will NOT be accepted.
• The Take-Home Test submission icon can be found in the top panel ( above Week 1) on FLO. Click on the icon and upload your assignment.
• Your submission should contain one (1) file in PDF format with size no bigger than 2 MB.
• You can update your submission for unlimited number of times before the due date.
• Refer to the “Statement of Assessment” pdf document on FLO regarding late assignment penalties.
• Medical extension or extension due to compassionate ground may be granted.
Only applications with legitimate reasons will be considered.
Writing Up Your Take-Home Test....
• Answer ALL questions in this Take-Home Test in the ORDER they appear. You are advised to start each question on a NEW PAGE.
• MS-WORD (or any other typesetting applications) can be used in preparing your Take-Home Test. Your submission MUST be in PDF format.
• INCLUDE relevant graphs, plots or tables in your answers.
• Graphs, plots and tables SHOULD be resized properly.
• A proper CAPTION must be included for every graph, plot or table. Units of measurements (if appropriate) and any other necessary details MUST also be included in the caption.
Brain size and autism [40 Marks]
Studies have linked brain size in infants and toddlers to a number of future ailments, including autism. One study looked at the brain sizes of 30 autistic boys and 12 non-autistic boys ( the control group), all of whom had undergone an MRI scan as toddlers. The data shown in the following are the whole-brain volumes (in millilitres) from the MRI scans. Investigate whether the mean whole-brain volume in early life is different between autistic and non-autistic boys.
Source: Courchesne, E., et al. (2001), “Unusual brain growth patterns in early life in patients with autistic disorder: an MRI study”, Neurology, 57, 245-254
Autistic
1311 1250 1292 1419 1401 1297 1202 1336 1308 1353
1515 1461 1365 1364 1362 1303 1278 1247 1333 1340
1319 1286 1223 1241 1229 1209 1171 1154 1128 1230
Control
1040 1180 1207 1179 1115 1133 1298 1263 1194 1198
1230 1114
Answer all the following questions (See ’Writing Up Your Take-Home Test’ in the cover page)
1. Construct the data-frame in EXCEL and import it to ”R”. For your answer, provide a screen-shot displaying the dataframe in ”R”. [5 Marks]
(Tips: Determine the number of subjects and the number of variables. Include sensible names for the vairables.)
(Instructions for the Screen-shot: Import the data to “R”. Display the data frame in ”R” by clicking on the ”view data set” button. Then, use ’print-screen’ (found on your keyboard) to copy the screen with the the data set; control-V to paste it in MS Word; click on the picture, select ’crop’ from the ’format’ tab and crop the picture; press ’ESC’ when finish cropping; resize the picture appropriately.)
2. Construct the appropriate conditional boxplots using ”R”. Give interpretation of the boxplots. [4 Marks]
3. State the aim of the investigation. [2 Marks]
4. What is the appropriate statistical procedure for this investigation? [2 Marks]
5. Write the null hypothesis in mathematical form; and in plain English. [4 Marks]
6. Write the alternative hypothesis in mathematical form; and in plain English. [4 Marks]
7. State the model assumption(s) and assess them. [10 Marks]
8. Perform the statistical procedure and present (copy and paste) all the results generated by “R”. Include all figures, plots and tables, if any. [2 Marks]
9. Interpret the p-value. [2 Marks]
10. Based on the results of the above statistical procedure, give a conclusion of the study.
[5 Marks]
* * * end * * * *
GET ANSWERS / LIVE CHAT