SOLUTION
We are asked to find the unit price for each bag of dog food Laura bought and to state which is a better buy based on the unit prices.
For the 7.48 kg of dog food at $15.84, the unit price is

Hence the answer is $2.12 to the nearest cent
For the 7.94 kg of dog food at $16.58, the unit price is

Hence the answer is $2.09 to the nearest cent
Therefore, the better buy is the 7.94-kg bag