Both of the previous two examples are incorrect. In order to receive a $1,600 benefit at age 62, your age 66 benefit would be $2,133. When you reduce 2,133 by 25% you arrive at a $1,600 benefit at age 62.
The following link shows the percentage reduction based on your year of birth. The reduction jumps to 30 percent if your normal retirement age is 67.
http://www.socialsecurity.gov/retire2/agereduction.htm