1. with Statistics Workshop with Statistics Workshop FunFunFunFun

2. Temasek Polytechnic School of Informatics & IT How the workshop works 3 hours @ Temasek Polytechnic –First 1.5 hours workshop on statistics –next 1.5 hours to create an interesting infographic to tell a story using the data.

3. Temasek Polytechnic School of Informatics & IT Why attend this workshop? Learn key statistics concepts that will help you make better decisions Pick up useful Microsoft Excel Skills Win attractive prizes!

4. Temasek Polytechnic School of Informatics & IT Stats in Action!

5. Temasek Polytechnic School of Informatics & IT Examples of Infographic

6. Temasek Polytechnic School of Informatics & IT Examples of Infographic

7. Temasek Polytechnic School of Informatics & IT Examples of Infographic

8. Temasek Polytechnic School of Informatics & IT What is Statistics ? Statistics is the study of the  Collection  Organization  Analysis  Interpretation of data

9. Temasek Polytechnic School of Informatics & IT Why Study Statistics? 1.Numbers are everywhere! 2.Statistical techniques are used to make decisions that effect our daily lives 3.How can stats affect you?

10. Temasek Polytechnic School of Informatics & IT Types of Statistics Statistics Descriptive Statistics Inferential Statistics

11. Temasek Polytechnic School of Informatics & IT Definition Descriptive Statistics – Methods of organizing, summarizing, and presenting data in an informative way. Examples: (Mean, Median, Mode), Frequency distribution table, Charts (Bar Chart, Line Chart), graphs (Histogram, Box-and-Whisker Plot) etc. Inferential Statistics – The methods used to estimate a property of a population on the basis of a sample. Example: Sampling

12. Temasek Polytechnic School of Informatics & IT Inferential Statistics  a research firm observes that women are twice as likely as men to shop impulsively.  an accountant observes that the current year’s total sales of $60 million represents a 20% increase compared to last year’s total sales. Which type of statistics is involved when... ANSWER : Descriptive Statistics

13. Temasek Polytechnic School of Informatics & IT Population and Sample Sample refers to a portion of the population. Population refers to a set or collection of all possible observations of some specific characteristics.

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15. Types of Variables Qualitative (Categorical responses) Quantitative (Numerical responses)

16. Temasek Polytechnic School of Informatics & IT Variable Definition 1. Qualitative variable: When the characteristic being studied is nonnumeric, it is called a qualitative variable. Examples are gender, state, country etc. It is discrete 2. Quantitative variable: When the variable studied can be reported numerically, the variable is called a quantitative variable. Examples are age, amount, no. of children etc. can be either discrete or continuous (a)Discrete variable: Individually separate and distinct. can only assume certain values and there are usually “gaps” between values. Example: Children in a family, number of students, number of employees etc. (b) Continuous variable: can assume any value within a specified range. Example: Amount, height, temperature etc.

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18. Levels of Measurement There are four levels of data: Nominal Ordinal Interval Ratio

19. Temasek Polytechnic School of Informatics & IT Definition 1.Nominal: variables which are classified into categories and order will be meaningless. Example: Race, Gender, Religious affiliations etc. Nominal level variables must be: (a) Mutually exclusive An individual object, can only belong to one category at a time. Not possible to have 2 categories at a single time. Can you be both F and M? (b) Exhaustive Each individual object must belong to either a F or M

20. Temasek Polytechnic School of Informatics & IT 2. Ordinal: Ordinal level variables are arranged in some order and the categories have some relationship among them. Example: Student’s grade, customer’s rating, military rank. Definition

21. Temasek Polytechnic School of Informatics & IT 3. Interval: Similar to the ordinal level, but there is a meaningful difference between values. 0 ≤ x ≤ 1 is an interval which contains 0 and 1, as well as all numbers between them Example: Temperature, Dress size, time Definition

22. Temasek Polytechnic School of Informatics & IT 4. Ratio: Practically all quantitative data is recorded as ratio level of measurement. Similar to the interval level, but has an absolute zero (0). Example: Number of employees, distance etc. Definition

23. Temasek Polytechnic School of Informatics & IT M.E.A.N M.E.D.I.A.N M.O.D.E

24. Temasek Polytechnic School of Informatics & IT Mean  the average value of the data set.  the most important and most frequently used measure of central tendency.  computed as the sum of all observed values divided by the total number of observations.

25. Temasek Polytechnic School of Informatics & IT Example Example The following shows the net profits of 12 branches of Evergreen Florist Shop on Mother’s Day. Net Profits ($) 903 1745 1883 863 1204 1624 1698 957 1041 1138 1354 1802 Compute the mean net profit assuming that data are from a population.

26. Temasek Polytechnic School of Informatics & IT Solution Population Data Population Mean 903+1745+1883+863+1204+1624+1698+957+1041+1138+1354+1802 12 Population Size 16212 12 $1,351 = = = sum of all observed values 1

27. Temasek Polytechnic School of Informatics & IT Median Compute the median for the following odd number of observations. 903 1745 1883 863 1204 1624 1698 957 1041 1138 1354 First arrange the data in an array ( in ascending order ) 863 903 957 1041 1138 1204 1354 1624 1698 1745 1883 = $1,204 Median= th observation in data array )( n + 1 2 )( 11+ 1 2 Median = th observation = 6 th observation Net Profits ($) of Evergreen Florist  Middle value in the data set

28. Temasek Polytechnic School of Informatics & IT Example Example Compute the median for the following even number of observations. 903 1745 1883 863 1204 1624 1698 957 1041 1138 1354 1895 First arrange the data in an array ( in ascending order ) 863 903 957 1041 1138 1204 1354 1624 1698 1745 1883 1895 = $1,279 Net Profits ($) of Evergreen Florist Median= th observation in data array )( n + 1 2 Median = 6.5 = 1204 + 1354 /2 2

29. Temasek Polytechnic School of Informatics & IT Mode Mode Determine the mode for the following data : Since the value occurs most frequently, Mode = $100,000 $5,000 $10,000 $20,000 $30,000 $50,000 $100,000 $100,000  the value that occurs most frequently.

30. Temasek Polytechnic School of Informatics & IT Example Example No Mode Raw data: 8 6 7 9 2 5 One Mode Raw data: 8 8 7 9 2 8 More Than One Mode Raw data: 8 8 7 9 2 9 Answer : No Mode 8 8 and 9 3

31. Temasek Polytechnic School of Informatics & IT Comparison of Mean, Median & Mode Comparison of Mean, Median & Mode mode median mean modemedian mean modemedian mean Distribution Skewed to Right or Positively Skewed Mean > Median Distribution Skewed to Left or Negatively Skewed Mean < Median Symmetrical Distribution or Normal Distribution Mean = Median = Mode For skewed distributions, the is the best measure as it lies between the mean and mode. MEDIAN 4

32. Temasek Polytechnic School of Informatics & IT Range Range The following shows the net profits of 12 branches of Evergreen Florist Shop on Mother’s Day. 903 1745 1883 863 1204 1624 1698 957 1041 1138 1354 1802 Find the range for the net profit. Range = Largest Value - Smallest Value Range = = 1883 - 863 $1,020 5

33. Temasek Polytechnic School of Informatics & IT Variance 1. Variance  the average of the squared distances of the observations from the mean. Population Variance Sample Variance

34. Temasek Polytechnic School of Informatics & IT What’s the difference? What is the difference between the 3 curves? Curve A Curve B Curve C They have same mean but different amount of spread (variability). So how far is each data value from the mean?

35. Temasek Polytechnic School of Informatics & IT Standard Deviation  most important and most commonly used measure of dispersion.  defined as the square root of variance, i.e. the square root of the average of the squared distances / deviations of the observations from the mean. 6

36. Temasek Polytechnic School of Informatics & IT Graphical Presentations of Data

37. Temasek Polytechnic School of Informatics & IT Histogram Histogram  a graphical presentation of a frequency distribution.  is constructed by (i) marking class intervals on the x-axis, and (ii) drawing rectangles whose heights correspond to the class frequencies.

38. Temasek Polytechnic School of Informatics & IT Histogram with 1 category

39. Temasek Polytechnic School of Informatics & IT Histogram with 2 categories (Group)

40. Temasek Polytechnic School of Informatics & IT Histogram with 4 categories ( Stacked) 7

41. Temasek Polytechnic School of Informatics & IT Frequency Polygon (Line Chart) Frequency Polygon (Line Chart)  is formed by letting the midpoint of each class represents the data in that class and then connecting the sequence of midpoints at their respective frequencies. 10 to 19 20 to 29 30 to 39 40 to 49 50 to 59 60 to 69 Frequency polygon showing daily sales turnover.

42. Temasek Polytechnic School of Informatics & IT Line chart with 1 category

43. Temasek Polytechnic School of Informatics & IT Line chart with 6 categories 8

44. Temasek Polytechnic School of Informatics & IT Area chart with 6 categories 9

45. Temasek Polytechnic School of Informatics & IT Pie Chart Pie Chart Total: 360º Number of Degrees Relative Value For Each Category of the Category  360 o   circular display divided into sections based on the number of observations.  useful in showing proportional relationships, such as market share & budgets. Total = 3000

46. Temasek Polytechnic School of Informatics & IT Example Example Pie Chart Showing the Ethnic Composition of Residents in ABC New Town Others (130) Chinese (2240) Malay (400) Indian (230) 10

47. Temasek Polytechnic School of Informatics & IT Pictogram Showing the Ethnic Composition of Residents in ABC New Town Chinese = 100 residents 130 230 400  a display that uses pictures or symbols to represent frequencies. Malay Indian Others 2240 Pictogram 11

48. Temasek Polytechnic School of Informatics & IT Scatter & Bubble Plot 12 Showing relation based on 2 dimensions

49. Temasek Polytechnic School of Informatics & IT Infographic Infographic (http://infogr.am/beta/)

50. Temasek Polytechnic School of Informatics & IT A Short Survey https://docs.google.com/forms/d/1kXw0_Rv LI-A5S- O6oTHC4svOsCtTtgU_DNz63mrgBqw/view form?usp=sharing&edit_requested=true

51. Temasek Polytechnic School of Informatics & IT Thanks!