Final answer:
Out of the three scenarios, a strong, 5-year economic expansion is least likely to occur with real GDP being less than potential GDP and an unemployment rate above the natural rate, as prolonged expansions typically coincide with increased real GDP and lower unemployment.
Step-by-step explanation:
Understanding the relationships between natural unemployment, potential real GDP, and economic cycles is essential when analyzing an economy. Of the three scenarios presented, (2) An economy in a strong, 5-year expansion is least likely to occur at the same time as the other two situations. Normally, during a prolonged economic expansion, the economy experiences growth in real GDP that brings it closer to or surpasses potential real GDP. Additionally, the unemployment rate typically decreases to around or below the natural rate of unemployment, reflecting a state closer to full employment rather than an unemployment rate above the natural rate.
Conversely, (1) Real GDP is less than potential GDP and (3) An unemployment rate above the natural rate of unemployment are more likely to be observed together because they both describe an economy that is performing below its full capacity. This usually occurs during economic downturns or recessions rather than during periods of robust growth.