Question

Needing to Find the Value of Y

Answer 1

The value of y is 360

Explanation:

Proportions

Two variables x and y are proportional if their quotient is a constant value:

`\displaystyle (y)/(x)=k`

From that definition, it follows:

`y=kx`

The problem states y=60 when x=3/4. This information is enough to find the value of k:

`\displaystyle (60)/(3/4)=k`

Operating:

`k=80`

The relation between y and x is, then:

`y=80x`

Now let's find the value of y when x=4 1/2. Since the value of x is given as a mixed fraction, we'll convert it to improper fraction:

`\displaystyle 4(1)/(2)=4+(1)/(2)=(9)/(2)`

Substituting in the relation:

`\displaystyle y=80(9)/(2)=360`

The value of y is 360