An average person in the united states throws away 4.5 × 10² g of trash per day. in 2013, there were about 3.2×106 people in the u. s.

about how many grams of trash was thrown away in the united states in 2013?

5.3 × 10^__ g

One person throws away 4.5 x 10² g/day.
In 2013, there were 3.2 x 10⁶ people, so they threw away
(4.5 x 10² g/day)*(3.2 x 10⁶) = 1.44 x 10⁹ g/day.

Assume that there were 365 days in 2013.
The total trash thrown away was
(1.44 x 10⁹ g/day)*(365 days) = 5.26 x 10¹¹ g

 5.3 x 10¹¹ g