Ancillary Statistics

Chapter 1: Introduction

Statistical Methods in Problem Solving Step 1: Step 2: Step 3: Step 4: Step 5: Identify Problems Plan and Collect Data Classify and Simplify Data Analyze Data Draw Conclusions

1.1

Definition of statistics

The word ‘statistics’ has 2 meanings. 1. Statistics refers to numerical facts. • The student population of UTAR is over 2000 in 2003. • The age of a student, the passing percentage of an examination. Statistics refers to the field or discipline of study. • Statistics is a group of methods that are used to collect, analyze, present, and interpret data and to make decisions.

2.

1.2

Types of Statistics

Statistics

Descriptive statistics

Inferential statistics

1.

Descriptive Statistics • Consists of methods for organizing, displaying, and describing data by using tables, graphs, and summary measures. • Deals with the description and analysis of a given group of data. • Present information in a convenient, usable and comprehensible form. Inductive Statistics (Inferential Statistics) • Consists of methods that use sample results to make decisions or predictions about a population. • Deals with the problems of making inferences or drawing conclusions about population based on information obtained from the samples taken from the population.

2.

Chapter 1 - 1

Ancillary Statistics

1.3

Population versus Sample

Population or Target Population Consists of all elements -- individuals, items, or objects -- whose characteristics are being studied. Sample A portion of the population selected for study. Example 1.1 Suppose we wanted to study the height of the students of UTAR. To do so, 100 students were selected randomly from all Faculties and their heights were measured. State the population and the sample.

Population Parameter A numerical measure (mean, median, mode, range, variance, standard deviation) calculated for a population data set. Sample statistic A summary measure...