DAC Fundamentals of Data Analytics 3

Question 1

What is a 'null value' in a dataset?

Accepted Answer

A missing or unknown value

Answer

A null represents missing or unknown data, which is distinct from zero.

Question 2

Which sampling method gives every member of a population an equal chance of selection?

Accepted Answer

Random sampling

Answer

Random sampling ensures each member has an equal probability of being chosen.

Question 3

A correlation coefficient of -0.9 indicates:

Accepted Answer

A strong negative relationship

Answer

A value near -1 indicates a strong inverse relationship between variables.

Question 4

What does 'ETL' stand for in data processing?

Accepted Answer

Extract, Transform, Load

Answer

ETL means Extract, Transform, Load — the process of moving data into a warehouse.

Question 5

Which data type would 'customer satisfaction rated 1 to 5' represent?

Accepted Answer

Ordinal

Answer

Ordinal data has a meaningful order but no consistent interval between ranks.

Data Analytics Certifications (DAC) Practice Test