Question

the interest earned on an account varies directly with the balance in the account. if an account with a balance of $200 earns $12.50 in interest, find the amount of interest earned on an account with a balance of $500

Answer 1

Answer:

$\ 31.25$

Step-by-step explanation:

A relationship between two variables, x, and y, represent a proportional variation if it can be expressed in the form $y/x=k$ or $y=kx$

Let

y-------> the interest earned on an account

x------>  the balance in the account

step 1

Find the constant k of proportionality

For $x=\ 200,y=\ 12.50$

$k=y/x$

substitute the values

$k=12.50/200=0.0625$

The equation is

$y=0.0625x$

step 2

Find the amount of interest earned on an account with a balance of $500

so

For  $x=\ 500$ substitute in the equation and solve for y

$y=0.0625(500)=\ 31.25$