Cluster sampling refers to a type of sampling method . With cluster sampling, the researcher divides the population into separate groups, called clusters. Then, a simple random sample of clusters is selected from the population. The researcher conducts his analysis on data from the sampled clusters.
If you are running around an actual football field (100 yds x 50 yds) a mile would be 5.9 laps (1 mi = 1760 yds/300 = 5.86667). A standard racetrack around a football field should be 440 yds, so 4 laps should be a mile there (1760/440 = 4).
How many football fields in an acre? People don't realize that one acre is the size of a football field According to my calculations if an American football field is 160 feet wide (53.3-repeating Yards), you would have an acre when you went from one goal line to just inside the 10 yard line at the other end (90.75 yards).