Finding the Fourth Proportional to 3,715.20, 5,610.60 and 3,715.20

Step by Step Solution

1. Step 1: Write the proportion equation
   3,715.20 : 5,610.60 = 3,715.20 : x
2. Step 2: Convert to fraction form
   3,715.20/5,610.60 = 3,715.20/x
3. Step 3: Cross multiply
   3,715.20x = 5,610.60 × 3,715.20
4. Step 4: Simplify right side
   3,715.20x = 20,844,501.12
5. Step 5: Solve for x
   x = 20,844,501.12/3,715.20
6. Step 6: Final answer
   x = 5,610.60