Finding the Fourth Proportional to 1,401.56, 1,934.16 and 780.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.56 : 1,934.16 = 780.56 : x
2. Step 2: Convert to fraction form
   1,401.56/1,934.16 = 780.56/x
3. Step 3: Cross multiply
   1,401.56x = 1,934.16 × 780.56
4. Step 4: Simplify right side
   1,401.56x = 1,509,727.93
5. Step 5: Solve for x
   x = 1,509,727.93/1,401.56
6. Step 6: Final answer
   x = 1,077.18