To find the percent error, we use this formula:
P
%
=
∣
∣
∣
e
−
t
t
∣
∣
∣
⋅
100
, where
P
%
is the percent error,
e
is the experimental or calculated value and
t
is the theoretical or known value.
http://astro.physics.uiowa.edu/ITU/glossary/percent-error-formula/
We have 2 known values, so plug them in to get
P
%
=
∣
∣
∣
250
−
240
240
∣
∣
∣
⋅
100
P
%
=
∣
∣
∣
10
240
∣
∣
∣
⋅
100
P
%
=
∣
∣
∣
1
24
∣
∣
∣
⋅
100
P
%
=
100
24
P
%
≈
4.1
¯
6
, therefore the percentage error is roughly 4.1
¯
6
percent.
I hope I helped!
