Answer:
The money supply decreases by $4,500.
Step-by-step explanation:
The amount of deposits is $8,000.
The required reserve ratio is 10%.
The amount of required reserve
= 10% of $8,000
=
![(10)/(100)* 8,000](https://img.qammunity.org/2020/formulas/business/college/l4j0odtbq0jfox5szb8idzwz57cbqtqu4b.png)
= $800
The amount to be loaned out
= Total deposit - Required reserves
= $8,000 - $800
= $7,200
The money supply is equal to money multiplier times the monetary base.
Money supply
=
![(1)/(RR) * Monetary\ base](https://img.qammunity.org/2020/formulas/business/college/of5gjagjzo7w2749aia08vvu06hnx4gref.png)
=
![(1)/(0.1)* \$ 7,200](https://img.qammunity.org/2020/formulas/business/college/2wiy3ajsm6gied0nu56bm1jxlbpmdl58r2.png)
= $72,000
So, the money supply before withdrawal is $72,000.
After withdrawal of $500, the deposits is
= $8,000 - $500
= $7,500
The amount of required reserve
= 10% of $7,500
=
![(10)/(100)* 7,500](https://img.qammunity.org/2020/formulas/business/college/ton5fsp3qgd22e2d8m33m48hjrlrtdgnt5.png)
= $750
The amount to be loaned out
= Total deposit - Required reserves
= $7,500 - $750
= $6,750
Money supply
=
![(1)/(RR) * Monetary\ base](https://img.qammunity.org/2020/formulas/business/college/of5gjagjzo7w2749aia08vvu06hnx4gref.png)
=
![(1)/(0.1)* \$ 6,750](https://img.qammunity.org/2020/formulas/business/college/87ja3txq8urpug4pf9ii75y8cywupjkpq3.png)
= $67,500
So, the money supply after withdrawal is $67,500.
The decrease in money supply
= $75,000 - $67,500
= $4,500