Answer
$\approx 306$ millions of U.S. residents
Work Step by Step
First class (0-9) population: $\approx42$ millions.
Second class (10-19) population: $\approx41$ millions.
Third class (20-29) population: $\approx43$ millions.
Fourth class (30-39) population: $\approx40$ millions.
Fifth class (40-49) population: $\approx44$ millions.
Sixth class (50-59) population: $\approx40$ millions.
Seventh class (60-69) population: $\approx28$ millions.
Eighth class (70-79) population: $\approx16$ millions.
Nineth class (80-89) population: $\approx10$ millions.
Tenth class (90-99) population: $\approx2$ millions.
$Total=42+41+43+40+44+40+28+16+10+2\approx 306$ millions.
