Understanding Histograms

What is a histogram?

• A type of graph that shows how often different values occur in a set of data

• A mathematical formula for calculating averages

• A method for recording qualitative data

• A pie chart showing percentages

What do you need to create a histogram?

• A set of data

• A ruler and a pencil

• A computer program

• A calculator

What does the horizontal or x-axis represent in a histogram?

• The average value of the data

• The frequency of data points

• The range of values for the data

• The total number of data points

What does the vertical or y-axis represent in a histogram?

• The frequency or how many in each range

• The median of the data

• The percentage of each category

• The range of values

Why do the bars in a histogram touch each other?

• To differentiate it from bar graphs

• To save space on the graph

• Because it is a requirement in graph design

• To show continuity of data

What can be inferred if a histogram bar is particularly high?

• It is irrelevant to the data set

• It represents a common range of data

• It indicates an error in data collection

• The value is an outlier

What does the presence of a very low bar (or no bar) in a histogram indicate?

• That range is very common

• There is an error in data

• The data is skewed

• Few or no occurrences of that range

How many students were greater than or equal to 60 inches tall?

• 21
• 11
• 17
• 6