Find Max value from datatable

I am using a write text file, in order to save it to a new notepad file. it will write out the highest number, but says it is 9, when the highest number is actually 980.304007

I have : row(“Close”).ToString.AsEnumerable().Max

it seems as if it is not returning the full value
and I also need to return the date associated with the highest value. I have attached the csv file I am talking aboutGOOG_YahooFinance_Data.xml (12.4 KB)