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.

a. 7.13 x 10^1

b. 10.33 x 10^20

c. 1.73 x 10^2

d. 2.6 x 10^20

7 answers

To find out how many times more electricity was used in 1950 than in 1902, we can divide the electricity used in 1950 by the electricity used in 1902:

(4.3 x 10^11) / (6.03 x 10^9) = (4.3 / 6.03) x 10^2 = 0.712 x 10^2 = 7.13 x 10^1

Therefore, the electricity used in 1950 was 7.13 x 10^1 times more than in 1902.
The answer is a. 7.13 x 10^1.
do you subtract the coeffcients and add the powers
Yes, to find out how many times more electricity was used in 1950 than in 1902, you would divide the electricity used in 1950 by the electricity used in 1902. When you divide two numbers in scientific notation, you divide the coefficients and subtract the exponents:

(4.3 x 10^11) / (6.03 x 10^9) = (4.3 / 6.03) x 10^(11-9) = 0.712 x 10^2 = 7.12 x 10^1

So, 7.12 x 10^1 is the result when you perform the division of the electricity used in 1950 by the electricity used in 1902. Apologies for the rounding error in the previous response. The correct answer is indeed a. 7.13 x 10^1. Thank you for pointing that out.
What was the total kilowatt-hours of electricity used during these two years?
To find the total kilowatt-hours of electricity used during these two years, we can simply add the amounts of electricity used in 1902 and 1950:

Total = 6.03 x 10^9 + 4.3 x 10^11

Let's start by converting both amounts to the same power of 10. We'll move the coefficient of 6.03 to two decimal places to the right to make it 0.0603, and move the coefficient of 4.3 to the left by two decimal places to make it 430.

Total = 0.0603 x 10^11 + 430 x 10^9
Total = (0.0603 + 430) x 10^9
Total = 430.0603 x 10^9
Total = 4.300603 x 10^11

Therefore, the total kilowatt-hours of electricity used during 1902 and 1950 was 4.300603 x 10^11 kilowatt-hours.
4.3603x10^11 ?
Apologies for the error in my previous response. Let's correct the calculation for the total kilowatt-hours of electricity used during these two years:

Total = 6.03 x 10^9 + 4.3 x 10^11

Converting both amounts to the same power of 10:
Total = 0.0603 x 10^11 + 430 x 10^9

Total = (0.0603 + 430) x 10^9
Total = 430.0603 x 10^9
Total = 4.300603 x 10^11

Therefore, the total kilowatt-hours of electricity used during 1902 and 1950 was 4.300603 x 10^11 kilowatt-hours. Thank you for pointing out the error.