Final answer:
In standard notation, 1.3 x 10^4 is 13,000, which is option B.
Step-by-step explanation:
The question asks to convert 1.3 x 10^4 into standard notation. To do this, we take the number 1.3 and move the decimal point to the right four places because the exponent on the 10 is 4. Moving the decimal point four places to the right turns 1.3 into 13,000.
In standard notation, 1.3 x 10^4 is 13,000. Therefore, among the given options, B. 13,000 is the correct answer.