1. Chapter One Introduction to Statistics

2. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 2 Some Commonly Asked Questions about Statistics

3. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 3 What Are Statistics? The word statistics refers to statistical procedures and the answers obtained from those procedures.

4. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 4 What Do Researchers Do with Statistics? Statistical procedures are used to –Organize, –Summarize, and –Communicate data Then to –Conclude what the data indicate

5. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 5 What Is Empirical Research? Empirical means knowledge obtained through observation of events. Empirical research involves measurement. The scores obtained in research are the data.

6. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 6 How Do I Learn Statistics? More than anything else, you need to learn when to use each statistical procedure, why each statistical procedure is used, and how to interpret its answer.

7. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 7 Basic Statistical Notation Statistical notation is the standardized code for symbolizing the mathematical operations performed in the formulas and the answers we obtain.

8. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 8 Review of Mathematics Used in Statistics

9. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 9 Mathematical Operations X or Y stand for each individual score obtained in a study. –Addition X + Y. –Subtraction X – Y. –Division X / Y. –Multiplication XY, ( X ) Y, or X ( Y ). “ X squared” or “ X times X. “the square root of X.”

10. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 10 Parentheses and square root signs indicate “the quantity” so always find the quantities indicated by these symbols first. The Order of Math Operations Unless otherwise indicated –Square or take the square root. –Multiply or divide. –Add or subtract.

11. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 11 Rounding Carry out calculations so that the final answer after rounding has two more decimal places than the original scores Do not round off at intermediate steps in a formula If the number in the next decimal place is 5 or greater than 5, round up If the number in the next decimal place is less than 5, round down

12. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 12 Transformations A transformation is a mathematical procedure for systematically converting a set of scores into a different set of scores.

13. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 13 Proportions A proportion is a decimal number between 0 and 1 that indicates a fraction of the total To transform a number to a proportion, divide the number by the total

14. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 14 Percents A percent (or percentage) is a proportion multiplied by 100 To transform a percent back into a proportion, divide the percent by 100

15. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 15 Creating Graphs The horizontal line across the bottom of a graph is the X axis The vertical line at the left-hand side is the Y axis

16. Copyright © Houghton Mifflin Company. All rights reserved.Chapter 1 - 16 Plot of Height and Weight Scores