Answer:
56 hours
Step-by-step explanation:
we know that
A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form
or
Let
x -----> the number of hours
y ----> the amount earned in dollars
This problem represent a proportional relationship between the variable x and the variable y
Find the value of the constant of proportionality k
For (3,27) ---->
For (9,81) ---->
For (21,189) ---->
The constant of proportionality k is 9
The linear equation is
For y=$500
substitute in the equation and solve for x
Divide by 9 both sides
we have

we know that


so



the answer is in thousandths, because the denominator of the multiplication of the two fractions is one thousand
Use this equation: Amount after years=Initial investment*(1+Interest rate/time compounded yearly)^number of years*times compounded yearly
So A=25,000(1+.095/1)^8*1
Simplify
A=25000(1.095)^8
Simplify
A=25000(2.07)
Solve
A=$51,671.73
This equation can be used for all problems of this type.