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).
High school, college and NFL football fields are the same size. A standard football field is 120 yards long. The playing field is 100 yards (300 feet) long, and each end zone is 10 yards (30 feet) deep. The field has a uniform width of 53 1/3 yards (160 feet). If you calculate the entire area of a football field, including the end zones, it works out to 57,600 square feet (360 x 160). One acre equals 43,560 square feet, so a football field is about 1.32 acres in size. The field is marked with a yard line every 5 yards, and every 10 yards is marked by a field number.