Which of the following Presidents put an end to dual federalism?

The ______, organized by the UN Conference on Environment and Development in Rio de Janeiro in 1992, was the largest gathering ever held on global environment issues and focused on adopting policies that would slow down the pollution of the earth.

Fill in the blank(s) with the appropriate word(s).

A country's mean income is always lower than its median income

Indicate whether this statement is true or false.