Cost of a Tour A club contract with a tour company arranges a tour to New York City....

Cost of a Tour A club contract with a tour company arranges a tour to New York City. The tour company requires that at least ten people register for the tour. The cost per person is $500. However, if more than 20 people register the cost per person will be reduced to $450. If more than 30 people register, the cost per person will be reduced to $400. Write a program that requests the number of registrants and calculates the total cost of the tour. Be sure to have the program check that the user entered a number into the top text box before clicking on the button. See Fig. 4.34.