What is the 'Arithmetic Mean' The arithmetic mean is a mathematical representation of the typical value of a series of numbers, computed as the sum of all the numbers in the series divided by the count of all numbers in the series. The arithmetic mean is sometimes referred to as the average or simply as the mean. Some mathematicians and scientists prefer to use the term arithmetic mean to distinguish it from other measures of averaging, such as the geometric mean and the harmonic mean.
HCG can be detected in urine or blood after implantation, which occurs on average 9 daye (range 6-12 days) after fertilization. Some home pregnancy tests claim to detect hCG as early as 4 days before the next expected period.
Pregnancy tests with a sensitivity of 20 mIU/ml are more sensitive than tests with 50 to 100 mIU/ml. Test brands will display how sensitive their tests are using mIU as the standard unit of measure. Test sensitivity equates with early-detection - and the lower the number, the sooner a test can detect pregnancy. The most sensitive pregnancy tests can detect hCG levels at as low as 20 mIU - or at around 8 days following implantation of the egg.