Week 1 - Introduction & Data

Question 1

What are qualitative data?

Answer 1

Also known as categorical data, they describe characteristics that fall into categories (e.g., gender, nationality, car color)

Question 2

What are quantitative data?

Answer 2

Numerical data that can be measured or counted (e.g., weight, income, height)

Question 3

What is the difference between nominal and ordinal qualitative data?

Answer 3

Nominal data: No meaningful order (e.g., nationality, gender)

Ordinal data: Meaningful order (e.g., customer satisfaction levels)

Question 4

What is the difference between discrete and continuous quantitative data?

Answer 4

Discrete: Takes only specific values (e.g., number of students in a class)

Continuous: Can take any value, including decimals (e.g., weight, time)

Question 5

What is a ratio variable?

Answer 5

A quantitative variable where ratios are meaningful, and zero means “none” (e.g., salary, weight, time)

Question 6

What is an interval variable?

Answer 6

A quantitative variable where ratios are not meaningful, and zero does not mean “none” (e.g., temperature in Celsius).

Question 7

What is the difference between cross-sectional and time-series data?

Answer 7

Cross-sectional: Collected at a single point in time (e.g., stock prices on a specific date)

Time-series: Collected over different time periods (e.g., stock prices over a year)

Question 8

What is primary data?

Answer 8

Data collected directly through experiments, interviews, or surveys

Question 9

What is secondary data?

Answer 9

Pre-existing data collected from sources like financial reports or published journals

Question 10

What is a population in statistics?

Answer 10

The complete set of all elements about which conclusions are drawn

Question 11

What is a sample in statistics?

Answer 11

A subset of the population used to estimate characteristics of the whole group

Question 12

What is statistical inference?

Answer 12

The process of using a sample to make generalizations about a population

Question 13

What is frequency in statistics?

Answer 13

The number of times a data value occurs

Question 14

What is relative frequency?

Answer 14

The proportion of occurrences of a data value compared to the total number of observations

Question 15

How do you calculate relative frequency?

Answer 15

RelativeFrequency(%)=

Totalnumberofobservations
Frequencyofaclass
​
×100