Finding the Fourth Proportional to 3,385.86, 5,079.15 and 920.72

Step by Step Solution

1. Step 1: Write the proportion equation
   3,385.86 : 5,079.15 = 920.72 : x
2. Step 2: Convert to fraction form
   3,385.86/5,079.15 = 920.72/x
3. Step 3: Cross multiply
   3,385.86x = 5,079.15 × 920.72
4. Step 4: Simplify right side
   3,385.86x = 4,676,474.99
5. Step 5: Solve for x
   x = 4,676,474.99/3,385.86
6. Step 6: Final answer
   x = 1,381.18