Did I round to the correct number of Sig figs?
18.0/83 x 100= 22%
15.87/149.87x 100= 11.3%
No, on the second one, you need four sig digits..
Tim O'connor?
To determine whether you rounded to the correct number of significant figures, we need to look at the original numbers and the final result.
For the first calculation:
18.0/83 x 100 = 21.686746987951807%
The original numbers are 18.0, 83, and 100. The number 18.0 has three significant figures (1, 8, and 0), while 83 and 100 have two significant figures each.
When dividing 18.0 by 83, you should use the least number of significant figures among the two original numbers, which is two in this case. So, the answer should be rounded to two significant figures.
Rounding 21.686746987951807% to two significant figures gives us 22%.
Therefore, you did round to the correct number of significant figures for the first calculation.
For the second calculation:
15.87/149.87 x 100 = 10.58167312218451%
The original numbers are 15.87, 149.87, and 100.
The number 15.87 has four significant figures (1, 5, 8, and 7), while 149.87 has five significant figures (1, 4, 9, 8, and 7).
When dividing 15.87 by 149.87, you should use the least number of significant figures among the two original numbers, which is four in this case. So, the answer should be rounded to four significant figures.
Rounding 10.58167312218451% to four significant figures gives us 10.58%.
Therefore, you did round to the correct number of significant figures for the second calculation as well.