The following are the weights for 3 different soil samples: 4.04 g, 3.9520 g, 4.065 g. how many significant figures will there be in the average of these soil weights?

3 significant figures

Explanation:

Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.

Rules for significant figures:

Digits from 1 to 9 are always significant and have infinite number of significant figures.

All non-zero numbers are always significant.

All zero’s between integers are always significant.

All zero’s preceding the first integers are never significant.

All zero’s after the decimal point are always significant.

The rule apply for equations involving both addition and division is the least precise number present after the decimal point determines the number of significant figures in the answer.

Average of weights =

Thus the average value of 4.02 has three significant figures as the least precise value of 4.04 has three significant figures.

pythagoras' theorem

square root (-5^2+9^2)

square root (25+81)

square root (106)

angle is tan^-1(9/5)

neg x, pos y