java

Q2 Using Bluej do the following: (3 Marks) a) Create an Interface called calculation with 4 variables a,b,c,d which accepts integer values and two methods Sum() \& Average(). b) Create an abstract class calculate1 which will implement the interface and declare a method multiply() c) Create a class calculate2 which will implement the Interface and display the sum and average of a,b,c,d. d) Create a class calculate3 which will extend the abstract class and implements the interface and display the product of a,b,c,d using multiply0,sum and average of a \& b using Sum0 \& Average 0