Any given demand or supply curve is based on the ceteris paribus assumption that .

All else is help equal, is the right answer.

Explanation:

“All else is help equal” is the correct answer because the demand curve is downward sloping and the supply curve is upward sloping. Here, the relationship between the price and demand is negative that means a rise in price leads to a fall in demand or vice versa. Similarly, in the case of supply, the price and supply are positively related that means a rise in price leads to a rise in supply or a fall in price lead to a fall in supply.  

the investment was $14,174.196

explanation:

a lump sum means that the father of the example made one deposit and leave it be.

we need to know the value of a capital that generated at 4.05% per year during 28 years the sum of $48,613.24

now clearing the formula to solve for capital we got:

and we reach the answer investment = $14,174.20

the answer is a. $209,000