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 x-axis st Quadrant 2 nd Quadrant 3 rd Quadrant 4 th 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) -

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.ineaindustry.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 (3/30)*100=10% = 5(5/30)*100=16.67% =11(11/30)*100= 36.67% =18(18/30)*100=60% =23(23/30)*100=76.67% =25(25/30)*100= 83.33% =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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