Chapter 8.5, Problem 8PPS

(a)

To determine

To explain: an equation relating the weight and the cost of the cheese.

Answer to Problem 8PPS

The equation is: $y=4.20x$

Explanation of Solution

Given:

Cost of 2 pounds is $8.40

Calculation:

Step 1: The number of pounds is denoted as x and cost of cheese is y

Now, if there is direct variation then there is some constant variable k such that it satisfies the equation: $y=kx$

So, put the value of $x=2$ and $y=8.40$ in equation to find the value of k

  $8.40=2k$

Divide the equation by 8.

  $\begin{array}{l}8.40=2k\\ 4.20=k\end{array}$

Step 2: use k to write an equation.

  $y=4.20x$

Conclusion:

Therefore, the equation is: $y=4.20x$

(b)

To determine

To find:the cost of 3.5 pounds of cheese.

Answer to Problem 8PPS

The cost of 3.5 pounds of cheeseis $14.7$

Explanation of Solution

Calculation:

Now, in order to calculate the cost of cheese

  $\begin{array}{l}y=4.20(3.5)\\ y=14.7\end{array}$

Conclusion:

Therefore, the cost of 3.5 pounds of cheeseis $14.7$