Answer
a, $108\times10^2$
b, $5.00\times10^6$
c, $1.35$
d, $0.0000345$
Work Step by Step
when rounding the numbers to three significant figures, we round up if the last digit dropped is 5 or more;
we round down if the if the last digit dropped is 4 or less
a, $10776.522$ = $107.76522\times10^2$
in our case the last digit dropped is 7, so we round it up to
$108\times10^2$
b, $4.999902\times10^6$ is rounded up to $5.00\times10^6$
c, $1.399999995$ is rounded up to $1.35$
d, $0.0000344988$ is rounded up to $0.0000345$
