Khan Academy: Analyzing categorical data

Question 1

What does it mean when two variables have “ no association”, or are “independent”?

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Answer 1

It means that P(A|B)=P(A)

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Ref 2 Example
For this quiz, no association between IVY school and taking piano is like saying:
if there’s no association (dependence) then:
P(IVY|Piano)= P(IVY)
or
P(Pinao|IVY)=P(Piano)

Question 2

What is meant by “two”-way frequency table?

Answer 2

Notice that there are two variables– gender and preference– this is where the two in two-way frequency table comes from.

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Question 3

What are two-way frequency tables good for?

Answer 3

Two-way relative frequency tables show us percentages rather than counts. They are good for seeing if there is an association between two variables.

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Question 4

Two-way relative frequency tables are useful when ____.

Answer 4

there are different sample sizes in a dataset

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Question 5

What is marginal distribution? How can it be represented?

Answer 5

The sum of the numbers row wise and column wise in a two-way table.
Can be represented as counts or percentages

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Question 6

What is conditional distribution? How can it be represented?(Percentage/Number/Both)

Answer 6

distribution of one variable given something true about the other variable.
It’s represented as precentages

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Question 7

Quizzes

Answer 7

Quizzes