1. Measures of Central Tendency Prepared by: Bhakti Joshi Date: November 21, 2011

2. Ogives Ages Frequency of Mobile Phones Owned Cumulative Frequency Percentage Cumulative Frequency 10 - 15 33(3/30)*100=10% 15 - 20 23+2 = 5(5/30)*100=16.67% 20 - 25 65+6=11(11/30)*100= 36.67% 25 - 30 711+7=18(18/30)*100=60% 30 - 35 518+5=23(23/30)*100=76.67% 35 - 40 223+2=25(25/30)*100= 83.33% 40 - 45 525+5=30(30/30)*100=100%

3. Frequency of mobile phones owned 10 15 20 25 30 35 40 45 1 2 3 4 5 6 7 8

4. Percentage Cumulative Frequencies of mobile phones owned 15 20 25 30 35 40 45 10 20 30 40 50 60 70 80 90 100

5. Ogives (Contd…) OGIVE

6. 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)

7. Mean or Arithmetic Mean (AM) Mean= 178/10 = 17.8 Interpretation?

8. Weighted Mean Age Intervals Frequency of Mobile Phones Owned (f) Mid- point (x) fx 10 - 1520 12.520*12.5= 250 15 - 2040 17.540*17.5= 700 20 - 2560 22.560*22.5=1350 25 - 3070 27.570*27.5=1925 30 - 3560 32.560*32.5=1950 35 - 4030 37.530*37.5=1125 40 - 4520 42.520*42.5=850 Interpretation? Weighted Mean= 27.16

9. Median …Central Item of a data set (N+1) /2 = M N = Number of observations M= Median

10. Median Age Intervals Frequency of Mobile Phones Owned (f) Cumulative Frequency 10 - 1520 15 - 204060 20 - 2560120 25 - 3070190 30 - 3560250 35 - 4030280 40 - 4520300 Interpretation?

11. Mode …Value that is repeated most often in the data set. Mode is not used for ungrouped data Age Intervals Frequency of Mobile Phones Owned (f) Cumulative Frequency 10 - 1520 15 - 204060 20 - 2560120 25 - 3070190 30 - 3560250 35 - 4030280 40 - 4520300 Interpretation?

12. Relationship between Mean-Median- Mode Mean < Median < Mode = Negatively Skewed Mean> Median> Mode = Positively Skewed Mean = Median = Mode = Normal

13. Projects Stock Prices of Companies representing any one of the following industries listed on the BSE or NSE Textiles Banking Automobiles IT/Telecommunication Pharmaceutical Foods & Beverages Infrastructure Steel Oil & Gas Chemicals

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