Types Of Statistics

Descriptive

Descriptive statistics focuses on organizing and summarizing data so it’s easier to understand. Think of it as a way to simplify data and highlight the key points.

Methods of Descriptive Statistics

Here are the two main methods used in descriptive statistics:

A. Measures of Central Tendency

These methods show the "center" or average of the data. There are three techniques:

Mean: The average value of the data.
Median: The middle value when the data is sorted.
Mode: The value that occurs most frequently.

B. Measures of Dispersion

These methods show how much the data varies or spreads out. There are two techniques:

Variance: Measures how far each number in the dataset is from the mean.
Standard Deviation: Shows the average amount of variation in the data.

These tools help us understand the main patterns and differences in our data.

Inferential

While descriptive statistics explains the data we already have, inferential statistics goes a step further. It helps us make predictions or conclusions about a bigger group using a smaller sample.

How Does It Work?

Sample Data: A small group of data collected for analysis.
Population Data: The entire group we’re trying to understand.

For example:

If you want to know the average height of people in your city, it’s impossible to measure everyone. Instead, you measure the heights of a smaller group (sample data) and use that to estimate the average height of the whole city (population data).

Techniques in Inferential Statistics

Some common methods to draw conclusions include:

Z-Test: Used when the sample size is large, and we know the population’s standard deviation.
T-Test: Used for smaller samples or when the population’s standard deviation is unknown.

These techniques help us understand big groups (populations) based on small, manageable samples.