To find the length of segment AC and round the result, round to the least precise measurement's decimal place. If 137.3 s is added to 70.90 s, giving a sum of 208.20 s, the final answer should be rounded to the tenths place, thus 208.2 s.
When determining the length of segment AC in a triangle and rounding the result, you must consider the precision of the measurements given. If you are adding figures such as 137.3 s, measured to the tenth place, and 70.90 s, measured to the hundredths place, the answer should be rounded to the tenths place, the least precise measurement. This is a key concept in measurements, as rounding should reflect the least precise value involved in a computation to ensure accuracy.
To illustrate, when measuring an object with a ruler that lacks millimeter markings, there may be some uncertainty in the tenths digit. For example, if an object falls between the 2 cm and 3 cm markings, the length might reasonably be reported as 2.5 cm, yet there is a possibility that another individual might estimate it to be 2.4 cm or 2.6 cm. Hence, when calculating lengths or performing other operations that require rounding, the value should always be rounded to match the least precise measurement to maintain consistency.
In the context of this problem, after adding 137.3 s and 70.90 s, which totals 208.20 s, the correct procedure would be to round down to 208.2 s to reflect the tenths place precision of the least certain value, which is 137.3 s.