Question

A calculator displays 3.9e – 4. How do you write 3.9e – 4 in standard form?

1) 3.9 × 10⁴
2) 3.9 × 10⁻⁴
3) 3.9 × 10⁵
4) 3.9 × 10⁻⁵

Answer 1

In order to convert 3.9e – 4 to standard form, move the decimal point 4 places to the left. So, the answer is 0.00039.

The correct option is 4) 3.9 × 10⁻⁵.

Step-by-step explanation:

To write 3.9e – 4 in standard form, we need to convert the given number from scientific notation to standard notation. In scientific notation, the number is expressed as the product of the coefficient and a power of 10. The power of 10 is represented by the exponent in the given expression. In this case, the exponent is -4.

To convert the given number to standard form, we move the decimal point in the coefficient to the right if the exponent is positive or to the left if the exponent is negative. Since the exponent is negative (-4), we move the decimal point 4 places to the left. So, 3.9e – 4 in standard form is equivalent to 0.00039.

Therefore, the correct option is 4) 3.9 × 10⁻⁵.