Answer:
Here is the TeeShirt class:
public class TeeShirt{  //class name 
    private int orderNumber;  // private member variable of type int of class TeeShirt to store the order number 
    private String size;  // to store the size of tshirt
    private String color;  //  to store the color of shirt
    private double price;  // to store the price of shirt
    public void setOrderNumber(int num){  //mutator method to set the order number 
        orderNumber = num;     }     
    public void setColor(String color){  //mutator method to set the color 
        this.color = color;        }      
        
      public void setSize(String sz){  //mutator method to set the shirt size 
    size = sz;  
    if(size.equals("XXXL") || size.equals("XXL")){  //if shirt size is XXL or XXXL
        price = 22.99;  // set the price to 22.99 if shirt size is XXL or XXXL
    }else{  //for all other sizes of shirt
        price = 19.99;     }  }  //sets the price to 19.99 for other sizes
    public int getOrderNumber(){  //accessor method to get the order number stored in orderNumber field
        return orderNumber;     }  //returns the current orderNumber
    public String getSize(){  //accessor method to get the size stored in size field
        return size;     }  //returns the current size
    public String getColor(){  //accessor method to get the color stored in color field
        return color;     }  //returns the current color
    public double getPrice(){  //accessor method to get the price stored in price field
        return price;      }  } //returns the current price
Explanation:
Here is the sub class CustomTee:
public class CustomTee extends TeeShirt
{  //class CustomTee that inherits from class TeeShirt
private String slogan;   //private member variable of type String of class CustomTee to store slogan 
public void setSlogan(String slgn)
{  //mutator method to set the slogan
slogan = slgn;
}
public String getSlogan()
{  //accessor method to get the slogan stored in slogan field
return slogan;}  } //returns the current slogan
Here is DemoTees.java
import java.util.*;
public class DemoTees{  //class name 
public static void main(String[] args)  {  //start of main method 
TeeShirt tee1 = new TeeShirt();  //creates object of class TeeShirt named tee1
TeeShirt tee2 = new TeeShirt();
//creates object of class TeeShirt named tee2
CustomTee tee3 = new CustomTee(); //creates object of class CustomTee named tee3
CustomTee tee4 = new CustomTee();  //creates object of class CustomTee named tee4
tee1.setOrderNumber(100);  //calls setOrderNumber method of class TeeShirt using object tee1 to set orderNumber to 100
tee1.setSize("XXL");  //calls setSize method of class TeeShirt using object tee1 to set size to XXL
tee1.setColor("blue");  //calls setColor method of class TeeShirt using object tee1 to set color to blue
tee2.setOrderNumber(101);  //calls setOrderNumber method of class TeeShirt using object tee2 to set orderNumber to 101
tee2.setSize("S");  //calls setSize method of class TeeShirt using object tee2 to set size to S
tee2.setColor("gray");  //calls setColor method of class TeeShirt using object tee2 to set color to gray
tee3.setOrderNumber(102);   //calls setOrderNumber method of class TeeShirt using object tee3 of class CustomTee to set orderNumber to 102
tee3.setSize("L");  //calls setSize method of class TeeShirt using object tee3 to set size to L
tee3.setColor("red");  //calls setColor method of class TeeShirt using object tee3 to set color to red
tee3.setSlogan("Born to have fun");  //calls setSlogan method of class CustomTee using tee3 object to set the slogan to Born to have fun 
tee4.setOrderNumber(104);  //calls setOrderNumber method of class TeeShirt using object tee4 of class CustomTee to set orderNumber to 104
tee4.setSize("XXXL");  //calls setSize method to set size to XXXL
tee4.setColor("black");  //calls setColor method to set color to black
tee4.setSlogan("Wilson for Mayor");  //calls setSlogan method to set the slogan to Wilson for Mayor
display(tee1);  //calls this method passing object tee1 
display(tee2);  //calls this method passing object tee2
displayCustomData(tee3);  //calls this method passing object tee3
displayCustomData(tee4);  }   //calls this method passing object tee4
public static void display(TeeShirt tee)
{  //method display that takes object of TeeShirt as parameter
System.out.println("Order #" + tee.getOrderNumber());  //displays the value of orderNumber by calling getOrderNumber method using object tee
System.out.println(" Description: " + tee.getSize() +  " " + tee.getColor());  //displays the values of size and color by calling methods getSize and getColor using object tee
System.out.println(" Price: $" + tee.getPrice());
}  //displays the value of price by calling getPrice method using object tee
public static void displayCustomData(CustomTee tee)
{  //method displayCustomData that takes object of CustomTee as parameter
display(tee);  //displays the orderNumber size color and price by calling display method and passing object tee to it 
System.out.println(" Slogan: " + tee.getSlogan());  }
} //displays the value of slogan by calling getSlogan method using object tee