Finding the Fourth Proportional to 1,401.70, 1,934.35 and 780.70

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.70 : 1,934.35 = 780.70 : x
2. Step 2: Convert to fraction form
   1,401.70/1,934.35 = 780.70/x
3. Step 3: Cross multiply
   1,401.70x = 1,934.35 × 780.70
4. Step 4: Simplify right side
   1,401.70x = 1,510,153.33
5. Step 5: Solve for x
   x = 1,510,153.33/1,401.70
6. Step 6: Final answer
   x = 1,077.37