What is statistics?

Introduction to Statistics

George Boorman

Curriculum Manager, DataCamp

What is statistics?

  • The field of statistics - the practice and study of collecting and analyzing data

 

  • Two main branches of statistics:

    • Descriptive/summary statistics - describing or summarizing our data
    • Inferential statistics - collect a sample of data, and apply the results to the population that the sample represents
Introduction to Statistics

Statistics is everywhere!

  • Sports statistics

 

 

 

  • Personal finances

football_stadium.jpg

 

piggy_bank_with_coins_around_it.jpg

1 Image credits: https://unsplash.com/@jesusance; https://unsplash.com/@andretaissin; https://unsplash.com/@unarchive
Introduction to Statistics

What can statistics do?

  • Allows us to answer practical questions:

    • What is the average salary in the USA?
    • How many customer inquiries is a company likely to receive per week?

 

  • It has applications across society:
    • Developing safer products such as cars or airplanes
    • Help governments understand the needs of a population

 

  • Validates scientific breakthroughs, such as Covid-19 vaccines
1 source: https://www.bmj.com/content/373/bmj.n1088
Introduction to Statistics

Limitations of statistics

  • Statistics requires specific, measurable questions:

    • Is rock music more popular than jazz?
    • On average, do women live longer than men?

  • We can't use statistics to find out why relationships exist

you_are_what_you_listen_to.jpg

1 Image credit: https://unsplash.com/@mohammadmetri
Introduction to Statistics

Types of data: numeric

  • Continuous data:
    • Stock prices
Stock Opening Price ($) Close Price {$}
Amazon.com, Inc 2328.14 2329.00
Apple Inc 156.77 157.04
Netflix Inc 188.32 188.75
  • Interval/count data:
    • How many cups of coffee do people drink per day?
Name Cups of coffee per day
Jessica 4
Andrew 2
Penny 3
1 Image credits: Stocks https://unsplash.com/@behy_studio
Introduction to Statistics

Visualizing numeric data

theft_vs_vehicle_crime_scatter_plot.png

1 Data source: Metropolitan Police Service, United Kingdom
Introduction to Statistics

Types of data: categorical

  • Nominal data:
    • Eye color
Name Eye color
Jessica Brown
Adam Green
Sarah Blue
  • Ordinal data:
    • How strongly do you agree that basketball is the best sport?

survey asking how strongly you agree that basketball is the best sport, with answers of strongly disagree/somewhat disagree/neither agree nor disagree/somewhat agree/strongly agree.png

1 Image credit: https://unsplash.com/@mango_quan
Introduction to Statistics

Visualizing categorical data

theft_by_greater_london_borough_bar_plot.png

Introduction to Statistics

Descriptive / Summary statistics

  • Describe or summarize data
Borough Number of Thefts Percentage of Total
Westminster 40,278 36.48%
Camden 18,928 17.15%
Southwark 17,309 15.68%
Hackney 17,121 15.51%
Newham 16,762 15.18%
Introduction to Statistics

Inferential statistics

  • Use a sample to draw conclusions about a population

  • How many people purchase clothing following social media advertising?

 

oneline_shopping_image_of_credit_card_and_laptop.png

1 source: https://unsplash.com/@pickawood
Introduction to Statistics

Let's practice!

Introduction to Statistics

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