Answer:
25%
Step-by-step explanation:
Given that,
Initial cost of a t-shirt = $30
Final cost of a t-shirt = $37.50
We need to find percent of change. The percentage change in any value is given by :
[tex]\%=\dfrac{\text{final value-initial value}}{\text{initial value}}\times 100\\\\=\dfrac{37.5-30}{30}\times 100\\\\=25\%[/tex]
Hence, the percentage error is 25%.