Why is the aggregate expenditure curve upward slopy?

The aggregate expenditure curve is upward sloping because it represents the relationship between total spending in an economy and the level of real GDP. As GDP increases, consumption, investment, and other components of expenditure typically rise due to higher incomes, leading to increased overall spending. This positive correlation shows that as economic output grows, so does the aggregate demand for goods and services, resulting in the upward slope of the curve.