graphs and measures of central tendency
DESCRIPTION
Graphs and Measures of Central Tendency. Prepared by: Bhakti Joshi Date: November 18, 2011. Type of Data. UNIVARIATE. Type of Data. COMPLEX. Graphs. y-axis. 2 nd Quadrant. 1 st Quadrant. 1 2 3 4 5 6 7 8. (- , +). (+ , +). (x , y). x-axis. - PowerPoint PPT PresentationTRANSCRIPT
Graphs and Measures of Central Tendency
Prepared by: Bhakti JoshiDate: November 18, 2011
Type of Data
Roll No. Age
1 182 183 184 185 196 167 188 179 1810 18
UNIVARIATE
Type of Data Mobile Brands Boys Girls
Total Students
Nokia 6 3 9Samsung 1 2 3BB 6 4 10Iphone 2 1 3HTC 0 1 1Sony 1 0 1Total Brands 16 11 27
COMPLEX
Graphsy-axis
x-axis1 2 3 4 5 6 7 8 9 10
1 2
3
4
5 6
7
8
-10 -9 -8 -7 -6 -5 -4 -3 -2 -1
-7
-6
-5
-4
-3
-2
-1
1st Quadrant2nd Quadrant
3rd Quadrant 4th Quadrant
(+ , +)(- , +)
(- , -) (+ , -)
(x , y)
Types of Graphs
• Lines• Histograms• Pie Charts
Ages of Students Across Roll Numbers
Source: Class Survey Conducted on November 11, 2011
Ages of Students Across Roll Numbers
• Students distributed around the age of 17?
• Students distributed around the age of 19?
• Which graph is visibly clear and why?
Mobile Brand Ownership Among Boys and Girls
Source: Class Survey Conducted on November 11, 2011
Mobile Brand Ownership Among Boys and Girls
Source: Class Survey Conducted on November 11, 2011
Mobile Brand Ownership Among Boys and Girls
• Which graph explicitly shows the total number of mobile brands owned by students?
• What are major differences in both the graphs in terms of :– Data presented– Interpretation
• What kind of questions can be answered by the graphs?
Market Share of Vehicles During FY11
Source: Society of Indian Automobile Manufacturers (SIAM)
Market Share of Vehicles During FY11
• Which type of vehicles in India have the least market share?
• If the total sales (in numbers) during FY11 was 15,513,156, how many passenger vehicles were sold?
• If the market share of commercial vehicles is expected to increase from 4.36% to 5% during FY12, while other vehicles’ shares remained the same what will be the expected total sales in FY12?
SENSEX - Movement on Daily Basis
Source: Bombay Stock Exchange (BSE) - www.bseindia.com
SENSEX - Movement on Daily Basis
• Identify the dates when the SENSEX peaked• What is the nature of the graph? Cyclical,
steady, or fluctuating?• During which time period were there limited
fluctuations?
Wholesale Price Index (WPI) – Monthly Data Series
Source: Ministry of Commerce, Office of Economic Adviser, Government of India (GoI) – eaindustry.nic.in
Wholesale Price Index (WPI) – Monthly Data Series
• What is WPI?• Is it increasing?• By what rate did WPI decline during Feb-11?• Which time period and by what rate was the
WPI the highest between Oct-10 and Oct-11?
Ogives
Ages
Frequency of Mobile Phones Owned
Cumulative Frequency
Percentage Cumulative Frequency
10 - 14 3 3 (3/30)*100=10%
15 - 19 2 3+2 = 5 (5/30)*100=16.67%
20 - 24 6 5+6=11 (11/30)*100= 36.67%
25 - 29 7 11+7=18 (18/30)*100=60%
30 - 34 5 18+5=23 (23/30)*100=76.67%
35 - 39 2 23+2=25 (25/30)*100= 83.33%
40 - 44 5 25+5=30 (30/30)*100=100%
Ogives (Contd…)OGIVE
Measures of Central Tendency
• Known as summary statistics• Description of numerical information• Analysis of information from the middle point
of a distribution and hence the term “Central Tendency”
• The starting point to analyse the spread of the data (Measure of Dispersion)
Frequency and Distribution Curve
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