Question

select the four numbers that are written using correct scientific notation.
24.6 x 10^-1
4.72 x 10^0
8.5 x 1^6
4.2 x 10^2
9 x 10^-3

Explanation:

Step1: Recall scientific - notation rules

Scientific notation is of the form $a\times10^{n}$, where $1\leq|a|\lt10$ and $n$ is an integer.

Step2: Analyze $24.6\times10^{-1}$

Since $24.6\geq10$, it is not in correct scientific - notation.

Step3: Analyze $4.72\times10^{0}$

Here, $1\leq4.72\lt10$ and the exponent of 10 is an integer. It is in correct scientific - notation.

Step4: Analyze $8.5\times1^{6}$

The base of the exponential part should be 10, not 1. So it is not in correct scientific - notation.

Step5: Analyze $4.2\times10^{2}$

Since $1\leq4.2\lt10$ and the exponent of 10 is an integer, it is in correct scientific - notation.

Step6: Analyze $9\times10^{-3}$

Since $1\leq9\lt10$ and the exponent of 10 is an integer, it is in correct scientific - notation.

Answer:

4.72 x 10^0, 4.2 x 10^2, 9 x 10^(-3)