Economics 2007 Jamb Examination

D. people within the working age.

The labour force refers to all individuals of working age who are either employed or actively seeking employment. It excludes children, the elderly beyond retirement age, and those not participating in the labour market.

This definition captures the active portion of the population that contributes to production and economic growth, making it a key indicator for labour market analysis.

C. average revenue.

In monopolistic competition, the demand curve faced by a firm is also its average revenue curve, since revenue per unit sold equals price. The curve labeled W in the diagram corresponds to this demand/AR relationship.

It slopes downward because the firm must lower price to sell more output, typical of imperfect competition structures.

C. 4.

From the table, total output increases up to 66kg with 4 workers, after which it stops rising. Beyond this point, additional workers do not increase output, showing diminishing returns.

Thus, the optimal number of workers to maximize productivity without waste is 4.

A. 8kg.

Marginal productivity is the additional output when one more worker is hired. Output increases from 52kg (with 2 workers) to 60kg (with 3 workers).

Therefore, MP = 60 - 52 = 8kg.

A. N7.40.

To find the mean, multiply each class mark by its frequency and divide by the total frequency:

(2×2 + 5×3 + 8×1 + 11×3 + 14×1) ÷ (2+3+1+3+1) = (4 + 15 + 8 + 33 + 14) ÷ 10 = 74 ÷ 10 = 7.4

Hence, the mean wage is N7.40.

sum of frequency = 2 + 3 + 1 + 3 + 1 = 10

Data set = 2, 2, 5, 5, 5,  8, 11, 11, 11, 14
Thus the median is between 5th and 6th element

\[median = \dfrac{5 + 8}{2} = 6.5 \]

The price per unit that the buyer pays is exactly the seller’s average revenue (AR). AR is defined as total revenue divided by quantity sold, which equals the market price at each unit sold in perfect competition.

A downward-sloping average revenue curve indicates that the firm faces a demand curve with varying elasticity. At different points, elasticity can range between zero (perfectly inelastic) and infinity (perfectly elastic).

Thus, the correct answer is: between zero and infinity.

In the short run, at least one factor of production is fixed, meaning the firm cannot vary all inputs. This leads to short-run costs since the firm must manage both fixed and variable costs together.

An increase in marginal cost means producers are less willing to supply at previous prices. This shifts the supply curve to the left because higher costs reduce the quantity supplied at each price level.