An online used car company sells second-hand cars. For 30 randomly selected transactions, the mean price is 2200 dollars.

Part a)Assuming a population standard deviation transaction prices of 100 dollars, obtain a 99% confidence interval for the mean price of all transactions. Please carry at least three decimal places in intermediate steps. Give your final answer to the nearest two decimal places.

my answers aren't working and I don't understand what I am doing wrong