When you put the earthworm farmers' salaries in numerical order to find the mean ($10,000, $18,000, $18,000, $19,000, $19,000, $19,000, $20,000, $20,000, $45,000), you discover that it is $19,000. That is more in line with what the majority of earthworm farmers in our example earn than the average or mean of $20,889.
The months November, December, January, Feburary, March and April are considered the months when the flu virus is most active. At this time you may experience symptoms like cold, chills, runny nose and congestion.
How does CDC monitor the progress of the flu season? CDC collects data year-round and reports on influenza (flu) activity in the United States each week from October through May. The U.S. influenza surveillance system consists of five separate categories.