First, launch NetBeans and close any previous projects that may be open (at the top menu go to File ==> Close All Projects).

Then create a new Java application called "Averager" (without the quotation marks) to get positive (i.e., any number greater than 0), double numbers from the user at the command line until they enter -1 (the sentinel). Use a do-while loop. Compute the average of the series of numbers and print the average to the command line. Don't include the sentinel in calculation of the average. Include suitable data validations for invalid data (e.g. the user enters a letter instead of a number), but stay in the loop until the sentinel is entered.