The key idea of the aggregate expenditure model is that in any particular year, the level of GDP is determined mainly by: a) export spending.
b) investment spending.
c) government spending.
d) the level of aggregate expenditure.

Ryan is deciding between attending western state university and eastern state university. he cannot attend both universities simultaneously. both are fine universities, but the reputation of western is slightly higher, as is the tuition. let mu subscript upper e and mu subscript upper w be ryan's marginal utilities from attending eastern and western state universities respectively and upper p subscript upper e and upper p subscript upper w be the prices of attending eastern and western state universities. using the rule of consumer optimum, ryan will decide to attend eastern state university, if mue/pe exceeds muw/pw attend eastern state university if mue/pe is less than muw/pw attend western state university, if pe/mue< pw/muw attend western state university, since it gives him more utility.