How to calculate my final grade?

ok, so I received a 93% for the first 3 quarters. Each quarter grade is 20% of my final grade. I got a 89% on the midterm, which is 10% of my final grade. I want to know what I have to get on my final (which is also 10%) if i get a 90, 89, or 88 as my 4th quarter grade to get an A as my final grade in this cl.