1. Write a program that computes the circumference of a circle with a radius of 12.5. The circumference is 2¼ times the radius, or about 2 times 3.141592654. 2. Modify the program from the previous exercise to prompt for and accept a radius from the person running the program. 3. Write a program that prompts for and reads two numbers, and prints out the result of the two numbers multiplied together. 4. Write a program that reads a string and a number, and prints the string the number of times indicated by the number on separate lines. (Hint: use the "x" operator).