To determine the total cost for 7 muffins and 14 juice boxes, we need to calculate the unit price for each item and then find the total cost.
Step 1: Calculate the unit price for muffins.
- Price for 6 muffins = $7.74
- Unit price for muffins = Total price / Number of muffins \[ \text{Unit price for muffins} = \frac{7.74}{6} \approx 1.29 \text{ (rounded to two decimal places)} \]
Step 2: Calculate the cost for 7 muffins. \[ \text{Cost for 7 muffins} = 7 \times 1.29 \approx 9.03 \]
Step 3: Calculate the unit price for juice boxes.
- Price for 8 juice boxes = $5.52
- Unit price for juice boxes = Total price / Number of juice boxes \[ \text{Unit price for juice boxes} = \frac{5.52}{8} \approx 0.69 \text{ (rounded to two decimal places)} \]
Step 4: Calculate the cost for 14 juice boxes. \[ \text{Cost for 14 juice boxes} = 14 \times 0.69 \approx 9.66 \]
Step 5: Calculate the total cost. \[ \text{Total cost} = \text{Cost for muffins} + \text{Cost for juice boxes} = 9.03 + 9.66 \approx 18.69 \]
The total cost for 7 muffins and 14 juice boxes is approximately $18.69.
Thus, the correct answer is: a. $18.69