Finding the Fourth Proportional to 1,401.76, 1,934.52 and 780.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.76 : 1,934.52 = 780.72 : x
2. Step 2: Convert to fraction form
   1,401.76/1,934.52 = 780.72/x
3. Step 3: Cross multiply
   1,401.76x = 1,934.52 × 780.72
4. Step 4: Simplify right side
   1,401.76x = 1,510,318.45
5. Step 5: Solve for x
   x = 1,510,318.45/1,401.76
6. Step 6: Final answer
   x = 1,077.44