Suppose that consumer spending initially rises by $$5$ billion for every $1$ percent rise in household wealth and that investment spending initially rises by $$20$ billion for every $1$ percentage point fall in the real interest rate. Also assume that the economy's multiplier is $3.$Instructions: Enter your answers as a whole number.a$.$ If household wealth falls by $4$ percent because of declining house values, and the real interest rate falls by $3$ percentage points, in what direction and by how much will the aggregate demand curve initially shift at each price level?Aggregate demand will initially shift $($Click to select$)$ v by $billion.b$.$ In what direction and by how much will it eventually shift?Aggregate demand will eventually shift $[($Click to select$)$ v by $$]$billion$.$