*TOPIC 1: INTRODUCTION

*

**is a branch of mathematics dealing with the collection, organizing, analysis, interpretation &

presentation of masses of numerical data.

*=>meaningful conclusions can be drawn from them.

*

**Descriptive statistics (learn about the data)

*Inferential statistics (learn about the population-assumption)

Whats the DIFFERENCE?

**Techniques that take the raw scores from a distribution and summarize them in a form

that is more manageable.

*characteristics of the data = described in simple terms.

*Methods = summarize, organize, simplify data.

**Include the construction of graphs, charts & tablesand the calculation of various descriptive measures

such as average (MEANS) and measure of variation

(STANDARD DEVIATION).

**Other name = statistical induction.*Comprises the use of statistics to make

inferences concerning some unknown aspect of

a population.

*mathematical tools to make forecasts and projections by analyzing the given data.

*

*Descriptive statistics*To describe the basic features of the data in a

study.

*To present quantitative descriptions in a manageable form.

*

*Inferential statistics*To study samples and then make generalizations

about the population from which they were

selected.

*

**Preliminary descriptive analysis of sample > choose the appropriate inferential method.

*Descriptive Statistics = *performed on a sample & on a population*To examine & explore the data

*Inferential Statistics =*An inference is made about the population based on

the samples data

*VARIABLES AND

DATA SETS

*A variable is property of an object or event that can take

on different values. It is a

characteristic associated

with each unit in a

population

*Constant:

*Discrete vs Continuous variable

*Quantitative data can be distinguished in terms they are discrete or continuous.

*

*Continuous Variable

*A variable that consists of numbers whose values, at least in theory has no restrictions.

*Example, weights of female statistics students, reaction time, standardized test score

*Continuous or Discrete??

*Cooking time for pasta-c*IQ score-c*Age -d*Population in Parit Raja-d*Speed of jetliner-c

**Quantitative Data*Qualitative Data

**Data is quantitative if the observations or measurements made on a given variable of a sample or population have

numerical values.

*Example: height, weight, number of children, blood pressure, current, voltage.

**is discrete if the corresponding data values take discrete values.

*Example : number of children, number of cars.

*is continuous if the data values take continuous values. *Example: speed, distance, time, pressure.

**Data is qualitative if words, groups and categories represents the observations or measurements.

*Example: colors, yes-no answers, blood group.

*Qualitative or Quantitative ?

*Race*Age*Family size*Academic major*IQ Score

*Net Worth (RM)*Favorite sport*Gender*Temperature

*Political preference

**Nominal*Ordinal*Interval*Ratio