Chapter 2 Distributions

Question 1

Mathmatical definition of mean

Answer 1

Question 2

When is an average not meaningful?

Answer 2

When there is no typical value, there are only groups of values at different ranges

Question 3

Mathmatical definition of variance?

Answer 3

Question 4

How is varience related to the standard deviation?

Answer 4

standard deviation is the square root of the varience.

Question 5

How is probability defined?

Answer 5

A frequency expressed as a fraction of the sample size, n.

Question 6

Good habit with new dataset?

Answer 6

Explore the variables that the researcher is planning to us one by one. One good way to compare is by histograms.

Question 7

5 Characteristics used to summarize distributions?

Answer 7

Central Tendency

Modes

Spread

Tails

Outliers

Question 8

Use of Cohen’s d

Answer 8

Used as an effetct size (the size of a difference between two populaitons)

Question 9

Cohen’s d mathmatical definition

Answer 9

Where x bar is the mean of population and s is the “pooled standard deviation” (seems similar weighted average)