Ivo Dinov UCLA Statistics, Neurology, LONI 

Statistics 157 Spring 2011 
Probability and Statistics Data
Modeling and Analysis using SOCR 
Department
of Statistics 
Instructor: Ivo Dinov 
Homework 1 
Due Date: Friday, April 08, 2011 


Time 
389 
356 
359 
363 
375 
424 
325 
394 
402 
373 
373 
370 
364 
366 
364 
325 
339 
393 
392 
369 
374 
359 
356 
403 
334 
397 
 How different are the samplemean and and samplemedian?
 By how much should the largest time be increased so that the sample median is half the sample mean?
 Use SOCR Charts to interactively compute/validate your answers (for example you can use the Index Chart).
14.5  25.6  52.4  66.3  69.3  69.8  76.2 
 What is the fivenumber summary for this data?
 Calculate the following sample measures of spread: variance, standard deviation and the meanabsolutedeviation.
 Validate your manuallycomputed results against the summaries reported in SOCR Charts.
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I.D.Dinov 2011 