2. Organizing, Visualizing and Describing Data

Question 1

Numerical vs Categorical Data?

Answer 1

Numerical: Values that can be counted or measured.
Categorical: Consist of labels that can be used to classify a set of data into groups.

Question 2

Types of numerical data?

Answer 2

Discrete: Countable (such as the months, days, or hours in a year)
Continuous: Can take any fractional value (e.g., the annual percentage return on an investment).

Question 3

Types of categorical data?

Answer 3

Nominal Data: Labels that cannot be placed in order logically. (fixed-income mutual funds may be classified as corporate bond funds, municipal bond funds, international bond funds)
Ordinal: Can be ranked in logical order. (the ranking of 1,000 small-cap growth stocks by performance may be done by assigning the number 1 to the 100 best-performing stocks)

Question 4

Time Series vs Cross Sectional?

Answer 4

Time Series: is a set of observations taken periodically, most often at equal intervals over time.
Cross-sectional: A set of comparable observations all taken at one specific point in time.