A specific good may be an inferior good for some ranges of income and a normal good for other ranges of income. For a really poor person or population (think undeveloped country), an increase in income may lead to greater consumption of noodles or rice. Now, if incomes rise a bit (think college student or developing country), more meat or seafood may become part of their diet. Over this range of incomes, noodles can be an inferior good and ground meat a normal good.