Test average added

src/test/java/src/TasksFrameTest.java

@@ -227,6 +227,17 @@ class TasksFrameTest {
         double c = tasksFrame.expo(10, 0);
         assertEquals(1, c);
     }
+
+    @Test
+    void test_average(){
+        TasksFrame tasksFrame = new TasksFrame();
+        double a = tasksFrame.average(12, 22, 46);
+        assertEquals(26.67, a);
+        double b = tasksFrame.average(55, 78, 92);
+        assertEquals(75, b);
+        double c = tasksFrame.average(0, 12, 38);
+        assertEquals(16.67, c);
+    }
 }