Finding the Fourth Proportional to 1,401.39, 1,933.89 and 780.39

Step by Step Solution

1. Step 1: Write the proportion equation
   1,401.39 : 1,933.89 = 780.39 : x
2. Step 2: Convert to fraction form
   1,401.39/1,933.89 = 780.39/x
3. Step 3: Cross multiply
   1,401.39x = 1,933.89 × 780.39
4. Step 4: Simplify right side
   1,401.39x = 1,509,188.42
5. Step 5: Solve for x
   x = 1,509,188.42/1,401.39
6. Step 6: Final answer
   x = 1,076.92