Mainstream economists model the demand for addictive goods by considering a person's utility from consuming an addictive good. Consider the following utility function, representing a person's preferences for consuming and addictive good (x1) and all other goods (x2):

U( x1,x2) =10xl^0.75 xz^0.25

1. Calculate the consumer's marginal utility from consuming the next unit of an addictive good.
2. Calculate the consumer's marginal utility from consuming the next unit of all other goods.
3. Calculate the marginal rate of substitution of consuming an addictive good for all other goods.
4. Suppose that a consumer is currently consuming 10 units of the addictive good and 7 units of other goods. Calculate the consumer's utility and the MRS at this bundle. Interpret your estimates.