12. The number 3.1 written as a percent is

Answer: D

Explanation:

3.1 written as a percent is 310%

To convert the number 3.1 into a percentage, you multiply it by 100, resulting in 310%. This conversion reflects the number's value as a part of a whole, expressed in terms of one hundred.

A) 0.03%

This option is incorrect because converting 3.1 to a percentage involves multiplying by 100, not dividing. Therefore, 0.03% does not represent the value of 3.1.

B) 0.31%

This option is also incorrect. The value 0.31% suggests that 3.1 is equivalent to 0.31 when, in fact, 3.1 is much larger and corresponds to 310% when correctly converted.

C) 31%

This option is incorrect as well. It misrepresents the value of 3.1; 31% would suggest that 3.1 is 31 parts out of 100, which does not accurately reflect its true percentage.

D) 310%

This option is correct. When 3.1 is converted to a percentage, it is achieved by multiplying 3.1 by 100, yielding 310%. This accurately captures the relationship of 3.1 to the whole.

E) 3100%

This option is incorrect because 3100% would imply that 3.1 is 31 times larger than the whole, which is not the case. The correct conversion gives us 310%, not 3100%.

Conclusion

The correct answer, 310%, accurately reflects the conversion of 3.1 into a percentage through multiplication by 100. All other options fail to represent the number correctly, either by underestimating or miscalculating its proportion as a percent. Thus, 310% is the definitive representation of the value when expressed in percentage terms.