Answer
$1.87×10^{-8}$
Work Step by Step
Rearrange Factors:
$=(3.972 \times 4.7)(10^{−5}÷10^{−4})$
Simplify:
$=18.6684×10^{−9}$
Convert to scientific notation:
$=1.86684 \times 10^{−8}$
Round to the appropriate number of significant digits:
$≈\boxed{1.87×10^{-8}}$
