DAC Data Analysis Fundamentals 3

Question 1

Which chart type best displays the proportion of a whole across a few categories?

Accepted Answer

Pie chart

Answer

A pie chart shows each category's share of a total.

Question 2

A correlation coefficient of -0.9 between two variables indicates what?

Accepted Answer

Strong negative relationship

Answer

A value near -1 signals a strong inverse (negative) linear relationship.

Question 3

What is the purpose of data normalization before analysis?

Accepted Answer

To scale features to a comparable range

Answer

Normalization rescales values so variables with different units can be compared fairly.

Question 4

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

Accepted Answer

Simple random sampling

Answer

Simple random sampling gives each unit an equal, independent selection probability.

Question 5

A histogram is most useful for showing what about a single numeric variable?

Accepted Answer

Its distribution

Answer

Histograms group values into bins to reveal the shape of a distribution.

Data Analytics Certifications (DAC) Practice Test