### Introduction

### Categories

Two broad categories of statistics that help in data analysis are:

### Descriptive Statistics

### Descriptive Statistics - Measures

**Measures of Central Tendency**

Focus on the average or central point of a dataset.

**Measures of Spread**

Focus on the dispersion of data from the central point.

### Inferential Statistics

### Inferential Statistics - Terms

**Estimation**

Process of analyzing the parameter of population.

**Point Estimation**

Single value that determines the parameter of population.

**Confidence Intervals**

Range of values within which the parameter is included.

**Hypothesis Tests**

Specific values of the parameter are tested.

### Inferential Statistics - Measures

**Estimation**

In this process, a sample is drawn from a population to estimate the following:

· **
Parameter:** Mean, Standard Deviation, Proportion, Correlation.

·
**Confidence Interval:** Range of values of an unknown population
parameter.

*Hypothesis Testing*

A hypothesis test helps in determining whether to reject or retain a claim about a population, depending on the evidence provided by a sample of data.

### Descriptive vs Inferential

Descriptive
Statistics |
Inferential
Statistics |
---|---|

Describes target population. | Produces inferences from samples. |

Analyzes and presents data in a meaningful manner. | Predicts the future. |

Conclusions are represented by forms, charts, and so on. | Conclusions are represented by probability scores. |

Tools: Measures of Central Tendency- Mean,
Median, Mode. |
Tools: Hypothesis Test. |