Answer
Find out the percent error in Annie's estimate .
To prove
Formula
As error = approx value - exact value
As given
Annie estimates that the height of a bookcase is 78.25 in.
The actual height is 75.50 in.
approx value = 78.25 in.
actual value = 75.50 in.
error = 78 .25 - 75 .50
= 2.75
put in the formula
Percentage error = 3.64 % (approx)
Therefore the Percentage error be 3.64 % (approx).