The data set available here contains masses for 100 circulating U. S. pennies. All pennies in these data sets were minted between 1962 and 1981, a period during which a penny’s composition was 95% copper and 5% zinc with a reported nominal mass of 3.11 g. Some pennies minted in 1982 and all pennies minted from 1983-present are 99.2% zinc (as the core) and 0.8% copper (as a coating), with a reported nominal mass of 2.5 g. The data set is available as an Excel file.
One use of the data is shown in the following histogram and superimposed normal distribution curve assuming that μ and σ2 for the population are equivalent to X and s2 for the sample. The total area of the histogram’s bars and the area under the normal distribution curve are equal.
