Answer:
If Lin's father has an 18% tip for the meal, he will need to pay an additional 0.18 x 23.89 = 4.3 dollars as a tip. This brings the total cost of the meal to 23.89 + 4.3 = 28.19 dollars.
Next, a 7% sales tax is applied to the total cost of the meal, which is 28.19 dollars. The amount of sales tax will be 0.07 x 28.19 = 1.97 dollars.
Therefore, the total amount that Lin's father will pay for the meal including the tip and sales tax is 28.19 + 1.97 = 30.16 dollars.
Explanation: