Yes you did those two correctly
When you estimate, you round each number, the add.
We round them to
700+620, which is 1320
So our non estimated answer is 1323
But our estimated answer is 1320
To answer the problem given above, divide the difference of the prices by the original price and multiply the answer by 100%. This is,
((22450 - 19450) / 19450) x 100% = 15.42%
Therefore, the percentage markup of the new car is approximately 15.42%.