## Understanding the Difference Between Sample and Population

• Overview • Populations are hard to observe • Samples are less time consuming and less costly
• Lets assume we walk to university canteen to collect the details from students who will be the sample • Sample has to have two important characteristics
• Randomness
• Representativeness • Students from canteen violate both randomness and representativeness.
• In this case how to draw a sample that is both random and representative, for this we need to have an access to university student database and then we choose sample out of it which are random & reprsentative.

## 10000 feet overview of descriptive and inferential statistics

• Descriptive Statistics

• 75% of the website traffic on flipkart.com is interested in mobiles
• (We have some data & we conducted statistics on that => concluded)
• Inferential Statistics

• According to survey which we conducted the average rent in hyderabad for 2 BHK will be 20000 by 2025
• (This study has taken a sample and predicted the observation for the whole population)

## Descriptive Statistics Fundamentals

• When we deal with statistics we deal with data
• Data is classified by
• Types of Data
• Categorical:
• This represents groups or categories
• Examples: Car Brands (BMW, Audi, Mercedes), Answer to yes/no questions
• Numerical: This represents numbers and is divided into two categories
• Discrete:
• This generally represent the data that can be usually counted in a finite matter
• Example: Number of cars, SAT score
• Continuous:
• This generally represents data which is not possible to count which we rather measure
• Example: Weight, height
• Measurement Levels
• Qualitative
• Nominal:
• Represents categories that cannot be put in any order
• Examples: Four seasons, Car brands
• Ordinal:
• Represents categories that cna be ordered
• Example: rating your meal (disgusting, unappetizing, neutral, tasty and delicious)
• Quantitative: Both represent numbers
• intervals:
• dont have true zeros
• Example: Degrees celsius and Fahrenheit
• ratios:
• Have true zero’s
• Example: lenght, degrees kelvin This site uses Akismet to reduce spam. Learn how your comment data is processed. 