DMC Data Visualization & Interpretation 2

Question 1

Which chart type is best suited for showing the distribution of a single continuous variable?

Accepted Answer

Histogram

Answer

A histogram bins continuous values and shows their frequency distribution.

Question 2

In a box plot, what does the box itself represent?

Accepted Answer

The interquartile range (Q1 to Q3)

Answer

The box spans the first to third quartile, containing the middle 50% of the data.

Question 3

A scatter plot shows points tightly clustered along a downward-sloping line. What does this suggest?

Accepted Answer

Strong negative correlation

Answer

Points along a downward line indicate that one variable falls as the other rises.

Question 4

Why is a truncated y-axis on a bar chart considered misleading?

Accepted Answer

It exaggerates differences between bar lengths

Answer

Bar length encodes magnitude, so a non-zero baseline visually exaggerates differences.

Question 5

Which visualization best shows correlations among many numeric variables at once?

Accepted Answer

Correlation matrix heatmap

Answer

A heatmap of the correlation matrix displays all pairwise coefficients with color intensity.

DMC - Data Mining Certification Practice Test