Just as on the demand side, the position of the supply can shift, say from a change in the price of a productive input or a technical improvement. The Law of Supply states that, in general, a rise in price leads to an expansion in supply and a fall in price leads to a contraction in supply.
Puberty takes place over a number of years, and the age at which it starts and ends varies widely. It generally begins somewhere between the ages of 7 and 13 for girls, and somewhere between the ages of 9 and 15 for guys, although it can be earlier or later for some people.
Growth and Development, Ages 15 to 18 Years. Growth and Development, Ages 15 to 18 Years. Growth and Development, Ages 15 to 18 Years. Teens grow and develop at different rates. But general teen growth and development patterns can be grouped into four main categories. Physical development. By age 15, most teens have entered puberty.