Answer:
Unrelated Goods
Step-by-step explanation:
From the question, we are been informed that If the purchases of shoes by someone decrease from 11 pairs per year to 9 pairs per year when the price of shirts increases from $8 to $12,
Then, in this case for me, shoes and shirts are considered as Unrelated Goods. Because the increase in the price of the shirts doesn't affect my demand for pair of shoes.
Unrelated Goods can describe as are goods with no relationship/connection that exist between them. The price of the first one doesn't affect the other one. With unrelated goods, the demands for the particular product is not altered by the price of the other product.