Worldwide, incomes began to rise dramatically around . even so, a historian has estimated
a
that in 1820, the average annual income in 2010 dollars was about that was sufficient income
for
but not enough for what most people today consider:

answer; no individual buyer or seller has any significant impact on the market price;

answer(c) factors of production;

answer: marginal utility of the fourth brownie is 0.

explanation: marginal utility is the addtional utility gained from the consumption of one more unit of a good. it is given by,

so, marginal utility at the 4th unit will be given by

since, the values are not given here, you can simply find marginal utility at fourth unit by subtracting total utility at 3rd unit from total utility at 4th unit.