Final answer:
To determine the number of T-shirts given away using cell K16, additional information such as the marginal utility and quantity of T-shirts and other goods is necessary. Without this, we cannot specify an exact function to use in cell K16, although the example of José losing 72 utils for 4 T-shirts provides a context for how utility might be calculated.
Step-by-step explanation:
To calculate the number of T-shirts given away using the appropriate function in cell K16, you would need to have more specific data about the T-shirts.
However, since the question references marginal utility, we can infer that the calculation involves economic concepts such as utility maximization or consumer choice theory.
If the aim is to calculate how many T-shirts one would surrender or acquire to maximize utility, you would use the marginal utility per T-shirt and compare it to other goods or services (such as movies in the scenario). Without additional context or numerical information, we cannot provide a specific function to use in cell K16.
For instance, if you need to determine utility lost from giving up T-shirts, you would take the number of T-shirts times the marginal utility of the last T-shirt given up.
This can be conceptualized in a scenario provided: if José gives up the fourth T-shirt, with a marginal utility of 18 utils, he loses 72 utils in total for 4 shirts (4 x 18).
However, to give a precise answer, the exact function to be used in cell K16 would depend on additional information from the scenario, such as the price of the T-shirts, the quantity of movies, budget constraints, or other pieces of data regarding the utility of different quantities of goods.