JAMB Economics Past Questions & Answers - Page 58

286.

X 2 3 4 5
F 2 5 2 1

From the table, the mean of the distribution is___________

A.

2.2

B.

2.5

C.

3.2

D.

4.5

Correct answer is C

Mean= ∑fx/∑f

=(4+15+8+5)/(2+5+2+1)

=32/10

=3.2

287.

X 8 10 12 16 18 20 24
F 2 1 4 3 3 1 6

From the table, Calculate the mean?

A.

24.0

B.

17.0

C.

18

D.

27.2

Correct answer is B

Mean= ∑fx/∑f

=(16+10+48+48+54+20+144)/(2+1+4+3+3+1+6)

=340/20

=17.0

 

By calculation, the mean of the distribution is not 18

288.

X 8 10 12 16 18 20 24
F 2 1 4 3 3 1 6

From the table, Calculate the median___________

A.

24.0

B.

17.0

C.

18

D.

16

Correct answer is D

When a group data is involved, cumulative frequency is used. The formula will be:

Median=[(N+1)/2]th

For member of odd number items. That is, where N is odd

Median=([N/2[N/2+1]th)/2

For member of odd number items. That is, where N is odd

Solution:

X 8 10 12 16 18 20 24
F 2 1 4 3 3 1 6
Cumulative Frequency 2 3 7 10 13 14 20

 

When a group data is involved, cumulative frequency is used. The formula will be:

Median=[(N+1)/2]th

For member of odd number items. That is, where N is odd

Median=([N/2[N/2+1]th)/2

For member of odd number items. That is, where N is odd

289.

No of Men 1 2 3 4 5 6 7 8  
Total Product(unit) 200 440 540 600 640 660 660 640

If the price per unit is N2, what is the average revenue when 6 men are employed?

A.

N110

B.

N120

C.

N220

D.

N330

Correct answer is A

Average revenue is obtained by dividing the total revenue by the number of units sold. Thus we have;

\(\frac{660}{6}\) = 110

290.

A market is in equilibrium when?

A.

There is no government intervention

B.

The demand is the same as the supply

C.

Buyers and sellers are free to sell more goods

D.

There is no free entry and exit

Correct answer is B

Market equilibrium is a market state where the supply in the market is equal to the demand in the market. The equilibrium price is the price of a good or service when the supply of it is equal to the demand for it in the market.