INTERPRETING A HISTOGRAM 

It is desired to describe the daily sales of a newspaper. A sample of sales for 70 days is obtained, and these are shown below. The sales are in 1000’s.

Obtain a histogram of these sales, and completely describe the histogram.

The Histogram below was created using StatCrunch. 

A histogram of Daily Newspaper Sales

Sales are in Thousands of Papers Sold per Day    

This newspaper typically sold about 100,000 copies per day. Sales between 90,000 and 110,000 were quite frequent.

For this sample of 70 days’ sales, the smallest number of newspapers sold was about 70,000 and the largest is about 150,000.

There were an unusually large number of newspapers sold one day. The day on which 150,000 newspapers were sold is atypical.

Finally, due to the atypical large value, the histogram is slightly skewed to the right, or positively skewed. Without this value, the histogram would be reasonably symmetric.

•  For this example, the interpretation is in terms of the variable of interest (newspapers sold per day). All statements refer to this variable, and the correct units of thousands of papers sold per day.  Every histogram should be interpreted in terms of the appropriate variable.  All parts of the interpretation should be phrased in complete sentences.

• In this example the variable of interest (newspapers sold per day) is quantitative.  It measures the number of copies sold per day.

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