Final answer:
To find the total cost of the dinner, multiply the cost of the meal by the tip percentage written as a decimal. Then, add the result to the cost of the meal.
Step-by-step explanation:
To find the total cost of the dinner, we need to add the cost of the meal to the tip amount. First, let's calculate the tip amount. Since the tip is 18% of the cost of the meal, we can convert the percentage to a decimal by dividing it by 100. So, 18% is equal to 0.18. Next, we multiply the decimal by the cost of the meal, which is $85.
Tip amount = $85 * 0.18 = $15.30
Now, we can find the total cost of the dinner by adding the cost of the meal and the tip amount.
Total cost = $85 + $15.30
Total cost = $100.30