Answer:
9 × 10⁻⁴
Explanation:
A number in scientific notation has the form A × 10ⁿ.
A is a number from 1 to 10, but not 10 itself and is called the coefficient.
n is an integer and is called the exponent.
10 000 has four zeros, so the exponent is 4.
However, your number is 9 ten thousandths, or 9/(10 000).
When the powers of 10 are in the denominator, the exponent is negative. In this case, the exponent is -4.
In scientific notation,
9 ten thousandths = 9 × 10⁻⁴