Data Visualization Statistical Visualization 2

Question 1

What does skewness indicate about a data distribution when visualized as a histogram?

Accepted Answer

The degree and direction of asymmetry around the distribution's central value

Answer

Positive skewness shows a long right tail (most values cluster left), while negative skewness shows a long left tail (most values cluster right).

Question 2

In a box plot, what do the 'whiskers' typically represent?

Accepted Answer

Data points within 1.5 × IQR from the first and third quartile

Answer

By default (Tukey's method), box plot whiskers extend to the most extreme data points within 1.5 times the interquartile range (IQR) from Q1 and Q3.

Question 3

What is the primary use of a funnel chart in business analytics?

Accepted Answer

Visualize the progressive reduction of values through sequential stages of a process

Answer

Funnel charts show drop-off rates through sequential stages (e.g., sales pipeline or conversion funnel), with width proportional to the number of items remaining at each stage.

Question 4

What does a residual plot in regression analysis reveal?

Accepted Answer

Whether the linear regression model adequately fits the data by showing patterns in errors

Answer

Residual plots show the difference between observed and predicted values; random scatter indicates a good fit, while patterns suggest model inadequacy or violated assumptions.

Question 5

What is the purpose of 'confidence interval bands' on a trend line visualization?

Accepted Answer

Indicate the uncertainty range within which the true trend line is likely to fall

Answer

Confidence interval bands (typically 95% CI) around a trend line show the range of values within which the true underlying trend is statistically likely to fall.

Data Visualization Practice Test

Data Visualization Practice Test

Data Visualization Statistical Visualization 2