Question

What variables other than price and advertising are likely to affect the quantity demanded of a product?

Answer 1

Need - generators in a power outage.

Answer 2

Usually quality is demanded of a product, not quantity.

If you are referring to the Demand Curve of "Supply and Demand", product quality, product reviews (now easily found on the internet), and "word of mouth" affect the number sold, as do price and advertising.

Answer 3

A decrease in aggregate supply means:
A. Both the real domestic output and the price level would decrease
B. The real domestic output would increase and rises in the price level would become smaller
C. The real domestic output would decrease and the price level would rise
D. Both the real domestic output and rises in the price level would become greater