Question

Difficulty: MediumBudget Line and Budget Constraint

A consumer allocates a monthly budget of ₦24,000 between Good XX (plotted on the horizontal axis) and Good YY (plotted on the vertical axis). The initial price of Good XX (PXP_X) is ₦1,200 per unit and the price of Good YY (PYP_Y) is ₦800 per unit. If the price of Good YY increases by 50%50\% while the consumer's income and the price of Good XX remain unchanged, what is the absolute slope of the new budget line?

  1. A
    1.50
  2. 1.00Answer
  3. C
    0.67
  4. D
    20.00

Answer

The absolute slope of the new budget line is 1.00.
The absolute slope of a budget line is given by the ratio of the price of the horizontal good to the price of the vertical good (PX/PYP_X / P_Y). After a 50% increase, the price of Good YY rises from ₦800 to ₦1,200. Dividing the price of Good XX (₦1,200) by the updated price of Good YY (₦1,200) gives an absolute slope of 1.00.

Step-by-Step Solution

1
Calculate the updated price of Good YY (PYP_Y')
PY=800+(0.50×800)=1,200P_Y' = ₦800 + (0.50 \times ₦800) = ₦1,200
The price of Good YY increased by 50%.
2
State the formula for the absolute slope of the budget line
Slope=PXPY\text{Slope} = \frac{P_X}{P_Y'}
The slope of a budget line with Good XX on the horizontal axis and Good YY on the vertical axis represents the relative price ratio PX/PYP_X / P_Y.
3
Substitute the price values into the slope formula
Slope=1,2001,200=1.00\text{Slope} = \frac{1,200}{1,200} = 1.00
Dividing the price of Good XX (₦1,200) by the new price of Good YY (₦1,200) yields the updated slope magnitude.

Key Concept

Budget Line Slope and Relative Price Ratio
Estimated Time:1m 30s
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