Answer:
The effective interest rate, rounded to the nearest tenth, is 0.1%.
Step-by-step explanation:
The banker's rule is the simple interest formula.
The simple interest formula is given by:
![E = P*I*t](https://tex.z-dn.net/?f=E%20%3D%20P%2AI%2At)
In which E are the earnings, P is the principal(the initial amount of money), I is the interest rate(yearly) and t is the time, in years.
The effective interest rate is given by the following formula:
.
In this problem, we have that:
A man makes a simple discount note for $6,200, at an ordinary bank discount rate of 8.84%, for 40 days. We consider that the year has 360 days. This means that
.
So
![E = 6200*0.0884*\frac{1}{9} = 60.9](https://tex.z-dn.net/?f=E%20%3D%206200%2A0.0884%2A%5Cfrac%7B1%7D%7B9%7D%20%3D%2060.9)
The effective interest rate is
![E_{IR} = \frac{E}{P} = \frac{60.9}{6200} = 0.0098 = 0.001](https://tex.z-dn.net/?f=E_%7BIR%7D%20%3D%20%5Cfrac%7BE%7D%7BP%7D%20%3D%20%5Cfrac%7B60.9%7D%7B6200%7D%20%3D%200.0098%20%3D%200.001)
The effective interest rate, rounded to the nearest tenth, is 0.1%.