Finding the Fourth Proportional to 72,408, 99,928.80 and 42,605.76

Step by Step Solution

1. Step 1: Write the proportion equation
   72,408 : 99,928.80 = 42,605.76 : x
2. Step 2: Convert to fraction form
   72,408/99,928.80 = 42,605.76/x
3. Step 3: Cross multiply
   72,408x = 99,928.80 × 42,605.76
4. Step 4: Simplify right side
   72,408x = 4,257,542,469.89
5. Step 5: Solve for x
   x = 4,257,542,469.89/72,408
6. Step 6: Final answer
   x = 58,799.34