# Question cb744

##### 2 Answers
Sep 17, 2017

$\text{Percentage Error} = 0.2$

#### Explanation:

Using Percentage Error Formula..

$\text{Percentage Error" = ("Actual value" color(white)x - color(white)x "Error")/"Actual value}$

$\text{Actual value} = 0.5$

$\text{Error} = 0.4$

$\text{Percentage Error} = \frac{0.5 - 0.4}{0.5}$

$\text{Percentage Error} = \frac{0.1}{0.5}$

$\text{Percentage Error} = 0.2$

Sep 17, 2017

%ρ = 0.9%

#### Explanation:

I think that the question means the percentage error (or uncertainty) in mass is 0.5 % and the percentage error in volume is 0.4 %

In that case we apply the uncertainty rules for determining the percentage error in density. The equation for density is:
ρ =m/V

The second rule for calculating uncertainty applies here, the percentage uncertainty of divided quantities is the sum of the individual percentage uncertainties. That means:
%ρ = %m +%V = 0.5% + 0.4% = 0.9%#