Need help here how to do this program write the definition of a method that takes as input three numbers and returns the sum of the first two numbers multiplied by the third number (Assume that the three numbers are of type double.) can anyone help me show how to do it?

I assume you can do the I/O

The calculation is

w = (x+y)*z

No I can not that is why I was asking for help to show me how

Sure! I can definitely help you with that. Here's an example of how you can write a method in Java to achieve that:

```java
public class Multiplication {
public static double getSumMultipliedByThird(double num1, double num2, double num3) {
double sum = num1 + num2;
double result = sum * num3;
return result;
}

public static void main(String[] args) {
double num1 = 2.5;
double num2 = 3.8;
double num3 = 4.2;

double finalResult = getSumMultipliedByThird(num1, num2, num3);
System.out.println("The result is: " + finalResult);
}
}
```

In this example, we define a class named `Multiplication`. Inside the class, we have a method called `getSumMultipliedByThird` that takes three double-type parameters: `num1`, `num2`, and `num3`.

Inside the method, we calculate the sum of `num1` and `num2` and store it in a variable named `sum`. Then, we multiply `sum` by `num3` and store the result in a variable named `result`. Finally, we return `result`.

In the `main` method, we create three variables `num1`, `num2`, and `num3` and assign some values to them. We then call the `getSumMultipliedByThird` method with these variables as arguments and store the returned result in a variable named `finalResult`. Finally, we print the value of `finalResult` using `System.out.println()`.

That's it! This program defines a method that takes three numbers, calculates the sum of the first two numbers, and multiplies it by the third number.