How to Calculate Maximum Error in a Sum with Uncertainties?

[Nerd10]

Homework Statement

Given a=11+/-0.5, b=0.04562+/-0.0001, c=17200+/-100. Find the maximum value of the absolute error in a+2b-c.

Homework Equations

absolute value of (0.5+2(0.0001)-(-100)=100.5002

11-0.5=10.5
0.04562-0.0001=0.04552
17200+100=17300
absolute value of (10.5+2(0.04552)-17300)=17289.40896

The Attempt at a Solution

Which of these answers is the correct answer? Is it 100.5002 or 17289.40896?

 

[phinds]

Homework Statement

Given a=11+/-0.5, b=0.04562+/-0.0001, c=17200+/-100. Find the maximum value of the absolute error in a+2b-c.

Homework Equations

absolute value of (0.5+2(0.0001)-(-100)=100.5002

11-0.5=10.5
0.04562-0.0001=0.04552
17200+100=17300
absolute value of (10.5+2(0.04552)-17300)=17289.40896

The Attempt at a Solution

Which of these answers is the correct answer? Is it 100.5002 or 17289.40896?

Well, are you trying to find the absoulte value of the sum or of the error?

 

[Nerd10]

Maximum value of the absolute error, just what the question asks. Which of the answers is right?

 

[phinds]

Well, what do the two numbers you came up with represent?