The executive branch is composed of the President, Vice President and Cabinet members. President The president is the head of state, head of the U.S. government and the commander-in-chief of the U.S. military.
Menarche. The average age of menarche, or first menstruation, in the United States is 12.88 years for Caucasian girls and 12.16 years for African American girls. A popular misconception is that menarche marks the beginning of puberty; in reality, menarche occurs later in puberty.
Results were expressed as the difference in age at menarche (months) relative to the average age at menarche, associated with each year delay of menarche in an older relative. On average, women were 46.4 years old at study entry (range 16 to 98 years), and the average age at menarche was 12.7 years.n average, women were 46.4 years old at study entry (range 16 to 98 years), and the average age at menarche was 12.7 years.