bigcity data frame has 49 rows and 2 columns.
The city data frame has 10 rows and 2 columns.
The measurements are the
population (in 1000's) of 49 U.S. cities in 1920 and 1930. The 49 cities are
a random sample taken from the 196 largest cities in 1920. The city data
frame consists of the first 10 observations in bigcity.
data(bigcity)Cochran, W.G. (1977) Sampling Techniques. Third edition. John Wiley