William adds two values, following the rules for using significant figures in computations. he should write the sum of these two numbers by using

It seems that you have missed the necessary options for us to answer this question, but anyway here is the answer. William adds two values, following the rules for using significant figures in computations. He should write the sum of these two numbers by using the same number of decimal places as the least precise value. Hope this helps.

While unproven, it uses facts to support part of a conclusion. it is still factual and has predictive power, however.