Question

Question 2 In this question you are asked to calculate probabilties for the discrete uniform and exponential distribution. Make changes to H3_Q2.java to accomplish the following tasks. a. Print a menu to the screen asking the user to either type the number 1 to choose "discrete uniform" or the number 2 to choose "exponential". The tool should print out an error message and exit if the user types in anything other than one of those two numbers. b. If the user selects discrete uniform, the program should request a lower bound a, an upper bound b and value of x from the user. Your code should check that all values are integers and that the upper bound is greater than the lower bound. The code should also check that a ≤ x ≤ b. c. If the user selects exponential then the program should request a value of λ and x. Your should check that both values are doubles and that x > 0. d. Using the distribution chosen by the user, calculate P(X = x) and P(X ≤ x) and display the results to the screen with appropriate labels.

Answer 1

Answer:

Hi there! The question is asking to make changes to the H3_Q2.java program however there is no such program attached. Nevertheless, the requirements in the question can be addressed in a new H3_Q2.java program that i've listed below.

Explanation:

We can use the Scanner util in Java for prompting user input. The method nextInt() and nextDouble() allow only values of types "int" and "double" respectively. I have used the "switch" statement to direct the program based on user selection of menu item. The checks are printed with the "System.out.println" command and the program exits in case of error or invalid input. Finally, the calculation of probability simply requires you to replace the comment with the formula for the probability calculation based on the method chosen.

H3_Q2.java

import java.util.Scanner;

public class H3_Q2 {

 public static void main(String args[]) {

   // print main menu for user selection

   System.out.println("Please type 1 to select 'discrete uniform' or 2 to select 'exponential'");

   Scanner scan = new Scanner(System.in);

   int selection = scan.nextInt();

   switch(selection) {

     case 1:

       // discrete uniform

       System.out.println("Please enter a lower bound value a: ");

       int a = scan.nextInt();

       System.out.println("Please enter a upper bound value b: ");

       int b = scan.nextInt();

       System.out.println("Please enter a value x: ");

       int x = scan.nextInt();

       if (b <= a) {

         System.out.println("The upper bound value b should be greater than the lower bound value a");

         System.exit(0);

       }

       if (a > x) {

         System.out.println("The value x should be greater than the lower bound value b");

         System.exit(0);

       }

       if (b < x) {

         System.out.println("The value x should be greater than the lower bound value b");

         System.exit(0);

       }

       break;

     case 2:

       // exponential

       System.out.println("Please enter a lambda value for exponential: ");

       double lambda = scan.nextDouble();

       System.out.println("Please enter a value x: ");

       double d_x = scan.nextDouble();

       if (d_x <= 0.0) {

         System.out.println("The value x should be greater than 0");

         break;

       } else {

         // calculate P(X = x) and P(X ≤ x)

         // result = calculateExponential()

         System.out.println("The calculation for the exponential method given the lambda value " + lambda + " and the value of x " + d_x + " is: ");

       }

       break;

     default:

       System.out.println("Invalid input. Exiting..");

       break;

   }

 }

}