Statistics
posted by Jerome on .
The archeological site of Tara is more than 4000 years old. Tradition states that Tara was the seat of the high kings of Ireland. Because of its archeological importance, Tara has received extensive study (Reference: Tara: An Archeological survey by Conor Newman, Royal Irish Academy, Dublin). Suppose an archeologist wants to estimate the density of ferromagnetic artifacts in the Tara region. For this purpose, a random sample of 55 plots, each of size 100 square meters, is used. The number of ferromagnetic artifacts for each plot is determined.
number of plots
size of the plots
the density of artifacts
number of ferromagnetic artifacts per 100 square meters
number of plots as well as size of the plot

"55 plots, each of size 100 square meters" gives the first two bits of information and possibly the last, however, I don't see data to allow you to provide the remaining answers.
Have you left out some data? 
It says to:
Identify the variable in the information here. Then it states the information provided above. 
The variable is the density of artifacts.