Answer: The cost per ounce of the peanut butter is $0.182.
Step-by-step explanation: Given that a grocery store sells an 18 ounce container of peanut butter for $3.28.
We are to find the cost per ounce of peanut butter.
We will be using the UNITARY method to solve the problem.
Cost of 18 ounces of peanut butter = $3.28.
So, the cost of 1 ounce of peanut butter is given by
![(3.28)/(18)=\$0.182.](https://img.qammunity.org/2019/formulas/mathematics/middle-school/oysmpensxuzgtrxcry8qghf67mjr57d9wd.png)
Thus, the cost per ounce of the peanut butter is $0.182.