Question

The use of electricity in the US in 1902 was 6.03 x 10^9 kilowatt-hours.

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

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

(1 point)
Responses

Subtract coefficients and divide powers: 1.73×102

Subtract coefficients and divide powers: 1.73×102


Divide coefficients and subtract powers: 1.4 x 102

Divide coefficients and subtract powers: 1.4 x 102


Multiply coefficients and add powers: 2.6×1021

Multiply coefficients and add powers: 2.6×1021


Divide coefficients and subtract powers: 7.13×101

Divide coefficients and subtract powers: 7.13×101


Add coefficients and add powers: 10.33×1020

Answer 1

(4.3×10^11) ÷ (6.03×10^9) = (4.3/6.03) × 10^(11−9) ≈ 0.713 × 10^2 = 7.13 × 10^1.

So the 1950 usage was 7.13×10^1 (about 71.3) times the 1902 usage.