Question

1. Marginal is the change in one variable due to a unit change in another. For example, the change in the X value from 2 to 3 is 1 or a "unit change", which leads to an increase in Y from 12 to 21 or a "marginal increase" in the Y value of 9. The symbol Δ (the Greek letter delta) means change in.

2. In economics we say that the Total of Y is 21 when X is 3. The value of Y is the Total (or sum) of the Marginal values, or in this case the change in Y (ΔY).


X Y Δ X Δ Y Average
Y Value
1 5 1 5
2 12 1 7
3 21 1 9
4 31 1 10
5 46 1 15

3. Fill in the table below, finding the marginal changes or totals. Remember the change in X is always a unit change.

X Y Δ X Δ Y Average
Y Value
3 27 9
4 32
5 35
6 1