The use of electricity in the US in 1902 was 6.03×10

Question

9
kilowatt-hours.

The use of electricity in the US in 1950 was 4.3×10
11
kilowatt-hours.

How many times more was the electricity used in 1950 than 1902? Express your answer in Scientific Notation.

(1 point)

Add coefficients and add powers : 10.33×10
20

Subtract coefficients and divide powers : 1.73×10
2

Divide coefficients and subtract powers : 1.4×10
2

Divide coefficients and subtract powers : 7.13×10
1

Multiply coefficients and add powers : 2.6×10
21

Answer 1

To determine how many times more electricity was used in 1950 compared to 1902, we divide the amount of electricity used in 1950 by the amount used in 1902.

1. Identify the values:

   • Electricity used in 1902: \( 6.03 \times 10^9 \) kWh
   • Electricity used in 1950: \( 4.3 \times 10^{11} \) kWh

2. Set up the division: \[ \text{Factor} = \frac{4.3 \times 10^{11}}{6.03 \times 10^{9}} \]

3. Divide coefficients: \[ \frac{4.3}{6.03} \approx 0.712 \]

4. Subtract exponents: \[ 10^{11 - 9} = 10^{2} \]

5. Combine: \[ \text{Factor} \approx 0.712 \times 10^2 \]

6. Convert to scientific notation: Since \( 0.712 \) is not in proper scientific notation, we move the decimal point one place to the right to get \( 7.12 \) and subtract 1 from the exponent. \[ 0.712 \times 10^2 = 7.12 \times 10^1 \]

Thus, the use of electricity in 1950 was approximately \( 7.12 \times 10^{1} \) times more than in 1902.

So the correct answer is: \[ \boxed{7.12 \times 10^{1}} \]