Estimate percent relative standard deviation equation numbers in parenthesis are absolute standard deviations. answer%RSD to two significant figures y = 6.75( 0.02 ) + 0.843 ( 0.003 ) -7.021( 0.002)

Question

Estimate percent relative standard deviation for the following calculation. The numbers in parenthesis are absolute standard deviations. Give answer as %RSD to two significant figures (do not include the percentage sign). y = 6.75( 0.02 ) + 0.843 ( 0.003 ) -7.021( 0.002 )

Answer 1

The absolute error adds in a Pythagorean way for addition and subtraction: δy = ( .02² +.003² + .002²)^1/2

The percent error is relative error written as a percentage is (δy/y)100

For multiplication or division, the relative errors add the same way as above. Take care.