Presentation is loading. Please wait.

Presentation is loading. Please wait.

1 - 1 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. What is Statistics?

Similar presentations


Presentation on theme: "1 - 1 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. What is Statistics?"— Presentation transcript:

1 1 - 1 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. What is Statistics?

2 1 - 2 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. When you have completed this chapter, you will be able to: Explain what is meant by statistics. Identify the role of statistics in the development of knowledge and everyday life. Explain what is meant by descriptive statistics and inferential statistics Distinguish between a qualitative variable and a quantitative variable.

3 1 - 3 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved Distinguish among the nominal, ordinal, interval, and ratio levels o f measurement. Collect data from published and unpublished sources. Identify abuses of statistics. Distinguish between a discrete variable and a continuous variable.

4 1 - 4 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved Gain an overview of the art and science of statistics. We recommend that you read this chapter at least twice, once at the beginning and once at the end of your course!

5 1 - 5 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. …it is the art and science of… collecting o rganizing p resenting data drawing inferences from a sample of information about an entire population as well as p redicting and developing policy analysis What is Meant by Statistics? What is Meant by Statistics?

6 1 - 6 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. in everyday life

7 1 - 7 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Who uses Statistics? Those using Statistical techniques include : Marketers Accountants Hospitals Investors Economists Sports people Statisticians Consumers Educators Quality Controllers Politicians Physicians

8 1 - 8 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Weather Forecasters Who uses Statistics?

9 1 - 9 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Who uses Statistics? Sports

10 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Types of Statistics

11 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Types of Statistics Methods of… collecting organizing presenting and analyzing data Methods of… collecting organizing presenting and analyzing data Science of… making inferences about a population, based on sample information. Descriptive Inferential

12 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Identify the following… C. Wine tasters sip a few drops of wine to make a decision with respect to all the wine waiting to be released for sale. A. A Gallup poll found that 83% of the people in a survey knew which country won the gold medal in Mens Hockey in B. The accounting department of a firm will select a sample of invoices to check for accuracy of all the invoices of the company. Descriptive Inferential

13 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. We start off with particular observations from the real world and draw conclusions about the general patterns in the real world! 1. Define the experimental goal or a working hypothesis 2. Design an experiment 3. Collect data 4. Estimate the values/relations 5. Draw inferences 6. Predict and prepare policy analysis Chapters 8 and 12 Chapters 3 and 4 Chapters 5,7,8 and 9 The Method of Experimentation

14 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Definitions & Assumptions Rules of Logic Implications or Hypotheses Objective or Working- Hypothesis Experimental Design & Data Collection Statistical Techniques Inductive Method Deductive Method The Method of Experimentation

15 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. A study was undertaken to estimate the average height of penguins in Antarctica. Lets review the steps they would take to prepare the estimate.

16 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

17 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. A population is a collection of all possible individuals, objects, or measurements of interest

18 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Take a What we now need is… From …which are deemed to be representative of the

19 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Take a Measurement for each one in the sample Take a Measurement for each one in the sample Record

20 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. …to put the data into a readable and understandable format! Displaying Data Results

21 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Two methods that can be used to see what the data conveys are Tables and Graphs/Charts More on these in chapter 2…

22 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Tables … are an efficient method of displaying data and depicting data accurately. e.g. More on these in chapter 2…

23 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Line Scatter Histogram Pie Bar More on these in chapter 2…

24 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Why take a sample instead of studying every member of the population? Costs of surveying the entire population may be too large or prohibitive Destruction of elements during investigation Accuracy of results More in chapter 8 …

25 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Data are everywhere Statistical techniques are used to make many decision that affect our lives No matter what your future line of work, you will make decisions that involve data. An understanding of statistical methods will help you make these decisions more effectively.

26 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

27 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Types of Data a characteristic of a population or sample a characteristic of a population or sample that is of interest to us A Variable

28 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Quantitative Qualitative Numerical Observations Categorical Observations Types of Data Variables

29 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Country of Birth U.K. Germany Taiwan China India Japan Russia Country of Birth U.K. Germany Taiwan China India Japan Russia Eye Colour Blue Brown Hazel Green Red Eye Colour Blue Brown Hazel Green Red Gender Male Female Gender Male Female Qualitative – or Attribute Variables

30 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Minutes to end of Class Minutes to end of Class Number of Children in a Family … Number of Children in a Family … Number of Two-Door Garages in a Street Number of Two-Door Garages in a Street Number of Satisfied Maple Leafs Fans … Number of Satisfied Maple Leafs Fans … Quantitative – Numeric Variables

31 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Quantitative Numerical Observations … can be classified as either Discrete or Continuous Discrete … can only assume certain values and there are usually gaps between values … can only assume certain values and there are usually gaps between values e.g. - Number of bedrooms in a house - Number of hammers sold (1,2,3,…etc) Variables Characteristics

32 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Continuous … can assume any value within a specified range! … can assume any value within a specified range! e.g. - Pressure in a tire - Weight of a pork chop - Height of students in a class Quantitative Numerical Observations … can be classified as either Discrete or Continuous Characteristics Variables

33 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Summary of Types of Variables Data Qualitative Categorical Observations Quantitative Numerical Observations Discrete Continuous (number of children)(time used for an exam)

34 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

35 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Statistical Abstracts Published Data Sources of Statistical Information Weather Sports

36 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Internet Sources of Statistical Information Government of Canada & Provinces

37 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. International Sources of Statistical Information IMF Organization for Economic Co-operation and Development

38 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. How to collect data… Commissioned surveys: Sources of Statistical Information To develop information for the survey that they are doing, pollsters often contact the selected sample population. For Example…At home, over the telephone, by mail, by , in the street, and at shopping malls!

39 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

40 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Nominal Ordinal Interval Ratio

41 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Nominal Data can only be classified into categories or counted and cannot be arranged in any particular order Example M & Ms Classification: Category: CandyCandy By Colour only (No natural order)

42 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Nominal Example M & Ms Exhaustive: Mutually Exclusive: …where an individual, object, or measurement is included in ONLY ONE CATEGORY …where each individual, object, or measurement MUST APPEAR in one of the categories

43 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Ordinal …involves data arranged in some order, but the differences between data values cannot be determined or are meaningless! Example During a taste test of 4 soft drinks: Mello Yello was ranked number……..…. 1. Sprite number……………………………. 2. Seven Up number..…………………..… Orange Crush number ….……………….4.

44 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Interval …similar to the Ordinal Level, with the additional property that meaningful amounts of differences between data values can be determined. There is no natural zero point Example Temperature on the Celsius scale.

45 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Ratio …the Interval Level with an inherent zero starting point. Differences and ratios are meaningful for this level of measurement. Examples Monthly income of surgeons Distance travelled by manufacturers representatives per month

46 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved.

47 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Benjamin Disraeli said… There are three kinds of lies… Benjamin Disraeli said… There are three kinds of lies…

48 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Figures dont lie. Liars figure! Caution

49 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. As you begin to study statistical methods, you are cautioned to take what you see published as statistical facts with a healthy grain of skepticism! As you begin to study statistical methods, you are cautioned to take what you see published as statistical facts with a healthy grain of skepticism! … an average may not be representative of all the data … graphs can also be misleading … be sure to study the sampling methods For Example Caution

50 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Caution Review the following three slides and notice the effect that the different scales have on your interpretation of the pattern between Crime and Unemployment Rates.

51 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved Crime Rate (in thousands) Unemployment Rate (%) Chart 1-11A

52 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved Crime Rate (in thousands) Unemployment Rate (%) Chart 1-11B

53 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved Chart 1-11C Crime Rate (in thousands) Unemployment Rate (%)

54 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. Test your learning … Click on… Online Learning Centre for quizzes extra content data sets searchable glossary access to Statistics Canadas E-Stat data …and much more!

55 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. This completes Chapter 1.


Download ppt "1 - 1 Copyright © 2004 by The McGraw-Hill Companies, Inc. All rights reserved. What is Statistics?"

Similar presentations


Ads by Google