Finding the Fourth Proportional to 3,139.60, 4,225.50 and 3,139.60

Step by Step Solution

1. Step 1: Write the proportion equation
   3,139.60 : 4,225.50 = 3,139.60 : x
2. Step 2: Convert to fraction form
   3,139.60/4,225.50 = 3,139.60/x
3. Step 3: Cross multiply
   3,139.60x = 4,225.50 × 3,139.60
4. Step 4: Simplify right side
   3,139.60x = 13,266,379.80
5. Step 5: Solve for x
   x = 13,266,379.80/3,139.60
6. Step 6: Final answer
   x = 4,225.50