Final answer:
To compare 7.2 E -3 and -6.8 E -4, we need to express both with the same exponent. After adjusting -6.8 E -4 to -0.68 E -3, we add it to 7.2 E -3 which gives us 6.52 E -3. The closest match to the correct answer from the given options is 7.26 E -3, option B.
Step-by-step explanation:
The student asked to compare the given scientific notations 7.2 E -3 and - 6.8 E -4. To do this, we first have to ensure that both numbers have the same exponent for the power of 10. Here's a step-by-step explanation to solve this:
- Convert -6.8 E -4 to the same exponent as 7.2 E -3. This means we will move the decimal place one to the right to make it -0.68 E -3.
- Now we can directly add the numbers: 7.2 (E -3) + (-0.68 E -3) = 6.52 E -3.
- Finally, we look at the options given to find the closest match to 6.52 E -3, which is option B, 7.26 E -3.
Therefore, the comparison between 7.2 E -3 and -6.8 E -4 results in a final answer closest to option B, which is 7.26 E -3.