Question

1. the radius of the planet neptune is approximately 15,300 miles. how is this number of miles written in scientific notation?

① ( 0.153 \times 10^5 )
② ( 0.153 \times 10^{-5} )
③ ( 1.53 \times 10^4 )
④ ( 1.53 \times 10^{-4} )

Explanation:

Step1: Define scientific notation rule

Scientific notation is $a \times 10^n$, where $1 \leq a < 10$, $n$ is integer.

Step2: Adjust 15,300 to valid $a$

Move decimal 4 places left: $15300 = 1.53 \times 10^4$

Step3: Match with options

Compare to given choices.

Answer:

C. $1.53 \times 10^4$