Answer
$0.0008$
Work Step by Step
To convert a number in scientific notation to a number in standard notation, we must move the decimal point to the left or right based on what power 10 is raised to. If the exponent is positive, we move the decimal right. If the exponent is negative, we move the decimal left.
We are trying to convert $8.0\times10^{-4}$ to standard notation. Since the exponent of $10$ is $-4$, we move the decimal point $4$ places to the left, giving us $0.0008$.
