Chapter 1 Question 1.11, Introduction to Java Programming, Tenth Edition Y. Daniel LiangY.

(Population projection) The U.S. Census Bureau projects population based on the following assumptions: ■ One birth every 7 seconds 

■ One death every 13 seconds 

■ One new immigrant every 45 seconds 

Write a program to display the population for each of the next five years. Assume the current population is 312,032,486 and one year has 365 days. Hint: In Java, if two integers perform division, the result is an integer. The fractional part is truncated. For example, 5 / 4 is 1 (not 1.25) and 10 / 4 is 2 (not 2.5). To get an accurate result with the fractional part, one of the values involved in the division must be a number with a decimal point. For example, 5.0 / 4 is 1.25 and 10 / 4.0 is 2.5.

Answer

//Program - 11

public class HelloWorld

{

    public static void main(String[] args)

    {

        System.out.println("Population projection");

        System.out.println("Current population: 312032486");

        System.out.println("One birth every 7 seconds.");

        System.out.println("One death every 13 seconds.");

        System.out.println("One new immigrant every 45 seconds.");

        System.out.println("Yearly Population projection formula: ");

        System.out.println("Current population + ((births per year)");

        System.out.println("                   - (deaths per year)");

        System.out.println("                   + (new immigrants per year))");

        System.out.println("                   * year.");

        System.out.println("Year 1 projection: ");

        System.out.println(312032486 + (((31536000 / 7)

                                     - (31536000 / 13)

                                     + (31536000 / 45)) * 1));

        System.out.println("Year 2 projection: ");

        System.out.println(312032486 + (((31536000 / 7)

                                     - (31536000 / 13)

                                     + (31536000 / 45)) * 2));

        System.out.println("Year 3 projection: ");

        System.out.println(312032486 + (((31536000 / 7)

                                     - (31536000 / 13)

                                     + (31536000 / 45)) * 3));

        System.out.println("Year 4 projection: ");

        System.out.println(312032486 + (((31536000 / 7)

                                     - (31536000 / 13)

                                     + (31536000 / 45)) * 4));

        System.out.println("Year 5 projection: ");

        System.out.println(312032486 + (((31536000 / 7)

                                     - (31536000 / 13)

                                     + (31536000 / 45)) * 5));

    }

}

OUTPUT

Population projection

Current population: 312032486

One birth every 7 seconds.

One death every 13 seconds.

One new immigrant every 45 seconds."

Yearly Population projection formula:

Current population + ((births per year)

                  - (deaths per year)

                  + (new immigrants per year))

                  * year.

Year 1 projection:

314812582

Year 2 projection:

317592678

Year 3 projection:

320372774

Year 4 projection:

323152870

Year 5 projection:

325932966