Use the following parameters in the IS$-$LM model to answer Questions $1-3$:

Interest elasticity of investment $=20$; marginal propensity to consume $=\frac{4}{5}$; marginal tax rate $=\frac{1}{4}$; income elasticity of demand for money $=\frac{1}{3}$; interest elasticity of demand for moncy$=10$; autoncmous money demand $=100$; price level $=2.$

Fiscal policy is twice effective as monetary policy.

$ $2.$ When government purchases and money supply are each increased by $520$ cedis, equilibrium level of income will increase by approximately $788$ units.

If government increases its purchases by $160$ units, investment will be crowded out by $110$ units.

If an economy can raise its annual real GDP growth rate from $3\mathrm{.}8$ percent to $4\mathrm{.}5$ percent, its real GDP doubling time is reduced by approximately $2\mathrm{.}8$ years.

In the Solow growth model, an increase in the marginal propensity to consume shifts the steadystate investment line downward with the implied change in the capital stock resulting in a lower standard of living in the long run.

Given that in the basic Solow growth model, $A=120,s=0\mathrm{.}11,n=0\mathrm{.}03,g=0\mathrm{.}07,$ and $=0\mathrm{.}08,$ the growth rate of GDP per effective labour, $($Y$/$AL$),$ in the steady state is $8$ percent.