Summarising Data: Tabular & Graphical Methods

These flashcards cover key concepts and definitions related to summarising data, focusing on both tabular and graphical methods.

What is Sturge's rule used for?

To determine the approximate number of classes for summarising quantitative data.

How is the approximate class width calculated?

Largest data value minus smallest data value, divided by the number of classes.

What is a histogram?

A type of chart for displaying quantitative data where classes are adjacent to each other without gaps.

What are the possible shapes of a histogram?

Symmetric, skewed to the left (negatively skewed), or skewed to the right (positively skewed).

What does a cumulative frequency distribution represent?

The number of data points with values less than or equal to the upper class limit of each class.

What is the first step in constructing a stem-and-leaf display?

Arrange the leading digits of each data point to the left of a vertical line.

How is the sample mean defined?

The sample mean is calculated as the sum of observations divided by the number of observations.

What is the formula for calculating the variance in a sample?

Variance is calculated as the average of the squared deviations from the mean, divided by n - 1.

What does the coefficient of variation measure?

It measures the standard deviation relative to the mean, expressed as a percentage.

What is an outlier?

A data point that is unusually large or small compared to the rest of the data.