Project 60
Project description

Consider the penny masses given in this data set.

  1. Create a histogram of all the penny masses in this data set, with a reasonable bin width. Don't forget to label the axes and include a title for the histogram.
  2. Describe the shape of this histogram.
  3. Explain the shape of this histogram by looking also at the other variable in the data set, the year of the penny.
  4. If you have done Project 58, mark the sample mean of these penny masses on the x axis of the histogram of penny masses.
  5. If you have done Project 58, indicate why the numerical summaries of penny masses computed in that problem are probably not particularly useful if we are interested in knowing about “the mass of a penny”.

Background on the data set
This data set consists of the years and masses of 100 randomly selected pennies (from a piggy bank in Tacoma, Washington), the masses being measured to the hundredth of a gram. The measurements were made one evening during the summer of 2008 using a MyWeigh Durascale (50 g by 0.01 g capacity). The order of the pennies in the data set is the order in which their masses were measured (which was randomly determined). The two variables and their units are summarized in the following table.
Variables in the data set
The variables in the data set are as follows:
NameUnitsDescription
yearyearsyear in which the penny was minted
massgramsmass of the penny
Link to the data set
The full data set in csv format is at:
http://hoard.projectivespace.com/datasets/pennies.csv