L see keller 31 for more discussion examples 25 key

Info icon This preview shows pages 24–37. Sign up to view the full content.

View Full Document Right Arrow Icon
l See Keller 3.1 for more discussion & examples
Image of page 24

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
25 Key features: Shapes of histograms l Symmetry l Left half of histogram is a mirror image of right half l Famous bell-shape is symmetric l Skewness l Asymmetric histogram l Long tail to the right ( positively skewed ) l Long tail to the left ( negatively skewed ) ? ? ? ? ? ? ? ? l May be associated with outliers l Number of modal classes l Modal class is class with highest frequency l Histograms may be unimodal or multimodal
Image of page 25
26 A key feature: Shapes of histograms… l From Keller Ex 3.2 l Histogram of returns on Investment A is … l Modal class is … l No. of modal classes? l Therefore histogram is …
Image of page 26

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
27 Bivariate relations l Want to extend univariate analyses to characterize relationships between variables l Contingency table (Cross-tabulation table) l For relationship between qualitative variables l Scatter plots l For relationship between quantitative variables l If one of the variables is “time” we get a time series plot (line chart)
Image of page 27
Mode of transport example: Staff/student differences? l What does the bar graph highlight? l Is there a better representation? Commuter type Mode Staff Student Total Resident 0 47 47 Walk 97 531 628 Cycle 52 158 210 Car 472 560 1032 Bus 186 1002 1188 Bus & train 230 2439 2669 Other 25 82 107 Total 1062 4819 5881 28 0 500 1000 1500 2000 2500 3000 Resident Walk Bike Car Bus Bus & train Other F req u en cy Mode of transport by commuter type Staff Students
Image of page 28

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
29 Scatter plots
Image of page 29
30 SIA: Cars in China
Image of page 30

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
31 SIA: Cars in China… l What are the key features of these data? l Read Keller Ch 3.4 l How does this graph rate in terms of “characteristics for graphical excellence”?
Image of page 31
32 Time series plot l Bivariate relationship between variable Y & time l With time series data order matters l Business cycles defined by extended periods of growth or contraction l SIA: Baby bonus l Relatively sophisticated time plot
Image of page 32

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
33 SIA: Petrol prices Quarterly unleaded petrol prices: December 1980 to December 2005 0 20 40 60 80 100 120 1982 Sept 1984 Sept 1986 Sept 1988 Sept 1990 Sept 1992 Sept 1994 Sept 1996 Sept 1998 Sept 2000 Sept 2002 Sept 2005 Sept Cents per litre Sydney Melbourne Brisbane
Image of page 33
34 SIA: Petrol prices… l What are the key features of these data? l Do these data inform motorists about the best time to buy petrol?
Image of page 34

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
35 SIA: Petrol prices…
Image of page 35
36 SIA: Petrol prices… l Pattern representative of daily price movements in Sydney in winter 2006 l Consider daily data June 11 2006-July 10 2006 l Notable price variation from day to day l Determine day of weekly peak and trough l Common day for prices to peak was Thursday l No peaks (or troughs) on Monday, Tuesday, Friday, Saturday or Sunday l Common day for prices to trough was Tuesday l Consider longer period of daily data (not shown) l No troughs on Wednesday, Thursday, Friday or Saturday l No days when prices both peaked & troughed
Image of page 36

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
37 SIA: Petrol prices… l Would bar or pie charts be useful in displaying the weekly peak & trough data?
Image of page 37
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern