Question

A calculator displays a result such as 1,365 248 0 107 kg. The estimated uncertainty in the result is 2%. How many digits should you include as significant when you write the result? Choose one:
1) zero,
2) one,
3) two,
4) three,
5) four
6) five,
7) the number cannot be determined.

Answer 1

Answer:

4) three

Explanation:

Assuming you mean 1.365248×10⁷, 2% of that is:

0.02 (1.365248×10⁷) = 0.027305×10⁷

So the number is:

1.365248×10⁷ ± 0.027305×10⁷

We need to round this number so that there is uncertainty only in the last digit.

1.37×10⁷ ± 0.03×10⁷

There are three significant figures in 1.37.