Finding the Fourth Proportional to 1,925.60, 2,658.12 and 1,139.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,925.60 : 2,658.12 = 1,139.72 : x
2. Step 2: Convert to fraction form
   1,925.60/2,658.12 = 1,139.72/x
3. Step 3: Cross multiply
   1,925.60x = 2,658.12 × 1,139.72
4. Step 4: Simplify right side
   1,925.60x = 3,029,512.53
5. Step 5: Solve for x
   x = 3,029,512.53/1,925.60
6. Step 6: Final answer
   x = 1,573.28